Toyota Avalon (XX50): Adaptive Variable Suspension System

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Suspension / Suspension Control / Adaptive Variable Suspension System

Front Acceleration Sensor RH Malfunction (C1715-C1717,C1796-C1798)

DESCRIPTION

The acceleration sensor (up and down G sensor) detects the upward and downward acceleration of the vehicle and outputs it as a voltage to the absorber control ECU.

The 3 up and down G sensors are installed in the driver side instrument panel, the passenger side instrument panel and the absorber control ECU.

Each up and down G sensor independently detects the upward and downward acceleration of the vehicle.

During a test mode inspection, the absorber control ECU reads the fluctuations in each sensor signal.

When a sensor signal does not fluctuate, test mode DTCs C1796, C1797 and C1798 remain stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1715	Front Acceleration Sensor RH Malfunction	One of the following conditions is met: With the engine switch on (IG), a voltage of 5.5 V or more, or 4.3 V or less is detected at the power source of the acceleration sensor assembly RH for 0.5 seconds. With the engine switch on (IG), a voltage of 4.7 V or more, or 0.3 V or less is detected at the acceleration sensor assembly RH for 1 second. Sensor output value is +/- 0.0639 m/s2 continuously for 300 seconds.	Acceleration sensor assembly RH Wire harness or connector Absorber control ECU	Does not come on	Yes
C1716	Front Acceleration Sensor LH Malfunction	One of the following conditions is met: With the engine switch on (IG), a voltage of 5.5 V or more, or 4.3 V or less is detected at the power source of the acceleration sensor assembly LH for 0.5 seconds. With the engine switch on (IG), a voltage of 4.7 V or more, or 0.3 V or less is detected at the acceleration sensor assembly LH for 1 second. Sensor output value is +/- 0.0639 m/s2 continuously for 300 seconds.	Acceleration sensor assembly LH Wire harness or connector Absorber control ECU	Does not come on	Yes
C1717	Rear Acceleration Sensor Malfunction	One of the following conditions is met: With the engine switch on (IG), a voltage of 5.5 V or more, or 4.3 V or less is detected at the power source of the rear acceleration sensor (absorber control ECU) for 0.5 seconds. With the engine switch on (IG), a voltage of 4.7 V or more, or 0.3 V or less is detected at the rear acceleration sensor (absorber control ECU) for 1 second. Sensor output value is +/- 0.0639 m/s2 continuously for 300 seconds.	Absorber control ECU	Does not come on	Yes
C1796	(Up&Down)G Sensor FR	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is not received from the acceleration sensor assembly RH for 1 second or more.	Acceleration sensor assembly RH Wire harness or connector Absorber control ECU	Test mode	(Test mode)
C1797	(Up&Down)G Sensor FL	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is not received from the acceleration sensor assembly LH for 1 second or more.	Acceleration sensor assembly LH Wire harness or connector Absorber control ECU	Test mode	(Test mode)
C1798	(Up&Down)G Sensor Rear	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is not received from the rear acceleration sensor (absorber control ECU) for 1 second or more.	Absorber control ECU	Test mode	(Test mode)

DTC Detection Conditions: C1715

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	Engine switch is on (IG)	○	○	○	○	○
Malfunction Status	Sensor power source voltage is 4.3 V or less	○	-	-	-	-
	Sensor power source voltage is 5.5 V or higher	-	○	-	-	-
	Output voltage is 0.3 V or less	-	-	○	-	-
	Output voltage is 4.7 V or higher	-	-	-	○	-
	Sensor output value is +/- 0.0639 m/s2	-	-	-	-	○
Detection Time		0.5 seconds or more	0.5 seconds or more	1 second or more	1 second or more	300 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip	1 trip

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

DTC Detection Conditions: C1716

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	Engine switch is on (IG)	○	○	○	○	○
Malfunction Status	Sensor power source voltage is 4.3 V or less	○	-	-	-	-
	Sensor power source voltage is 5.5 V or higher	-	○	-	-	-
	Output voltage is 0.3 V or less	-	-	○	-	-
	Output voltage is 4.7 V or higher	-	-	-	○	-
	Sensor output value is +/- 0.0639 m/s2	-	-	-	-	○
Detection Time		0.5 seconds or more	0.5 seconds or more	1 second or more	1 second or more	300 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip	1 trip

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

DTC Detection Conditions: C1717

		Vehicle Condition
		Pattern 1	Pattern 2	Pattern 3	Pattern 4	Pattern 5
Diagnosis Condition	Engine switch is on (IG)	○	○	○	○	○
Malfunction Status	Sensor power source voltage is 4.3 V or less	○	-	-	-	-
	Sensor power source voltage is 5.5 V or higher	-	○	-	-	-
	Output voltage is 0.3 V or less	-	-	○	-	-
	Output voltage is 4.7 V or higher	-	-	-	○	-
	Sensor output value is +/- 0.0639 m/s2	-	-	-	-	○
Detection Time		0.5 seconds or more	0.5 seconds or more	1 second or more	1 second or more	300 seconds or more
Number of Trips		1 trip	1 trip	1 trip	1 trip	1 trip

HINT:

DTC will be stored when the conditions of any pattern in the table above are met.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.
Click here
Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
  Click here
- DTC inspection.
  Click here
- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here

PROCEDURE

1.	READ VALUE USING TECHSTREAM ((UP & DOWN) G SENSOR)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Data List.

Chassis > Air suspension > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

(Up&Down)G Sensor FR

Front acceleration sensor RH (up and down)

Min.: -1045.29 m/s2

Max.: 1045.26 m/s2

-0.98 to 0.98 m/s2

when stationary

The value changes when the vehicle (front RH) is bounced.

(Up&Down)G Sensor FL

Front acceleration sensor LH (up and down)

Min.: -1045.29 m/s2

Max.: 1045.26 m/s2

-0.98 to 0.98 m/s2

when stationary

The value changes when the vehicle (front LH) is bounced.

(Up&Down)G Sensor Rear

Rear acceleration sensor (up and down)

Min.: -1045.29 m/s2

Max.: 1045.26 m/s2

-0.98 to 0.98 m/s2

when stationary

The value changes when the vehicle (rear) is bounced.

Chassis > Air suspension > Data List

Tester Display
(Up&Down)G Sensor FR
(Up&Down)G Sensor FL
(Up&Down)G Sensor Rear

OK:

The values are as specified in the normal condition column.

Result	Proceed to
OK	A
NG (front RH or front LH)	B
NG (rear)	C

GO TO STEP 3

REPLACE ABSORBER CONTROL ECU

2.	CHECK FOR DTCS

(a) Clear the DTCs.

Click here

Chassis > Air suspension > Clear DTCs

(b) Turn the engine switch off.

Click here

Chassis > Air suspension > Trouble Codes

Result	Proceed to
DTCs are output (front RH or front LH)	A
DTCs are output (rear)	B
DTCs are not output	C

REPLACE ABSORBER CONTROL ECU

USE SIMULATION METHOD TO CHECK

3.	INSPECT ACCELERATION SENSOR ASSEMBLY

(a) Turn the engine switch off.

(b) Remove the acceleration sensor assembly RH or acceleration sensor assembly LH.

Click here

Result	Proceed to
OK	A
NG (Acceleration sensor assembly RH malfunction)	B
NG (Acceleration sensor assembly LH malfunction)	C

REPLACE ACCELERATION SENSOR ASSEMBLY RH

REPLACE ACCELERATION SENSOR ASSEMBLY LH

4.	CHECK HARNESS AND CONNECTOR (ACCELERATION SENSOR ASSEMBLY - ABSORBER CONTROL ECU)

(a) Check the acceleration sensor assembly RH harness and connector (when DTC C1715 is output).

(1) Disconnect the K59 absorber control ECU connector.

(2) Disconnect the K61 acceleration sensor assembly RH connector.

(3) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
K61-1 (SGFR) - K59-23 (SGS1)	Always	Below 1 Ω
K61-2 (SGG) - K59-22 (SGG1)	Always	Below 1 Ω
K61-3 (SGB) - K59-14 (SGB1)	Always	Below 1 Ω
K61-1 (SGFR) or K59-23 (SGS1) - Body ground	Always	10 kΩ or higher
K61-2 (SGG) or K59-22 (SGG1) - Body ground	Always	10 kΩ or higher
K61-3 (SGB) or K59-14 (SGB1) - Body ground	Always	10 kΩ or higher

(b) Check the acceleration sensor assembly LH harness and connector (when DTC C1716 is output).

(1) Disconnect the K59 absorber control ECU connector.

(2) Disconnect the A46 acceleration sensor assembly LH connector.

(3) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
A46-1 (SGFL) - K59-25 (SGS2)	Always	Below 1 Ω
A46-2 (SGG) - K59-24 (SGG2)	Always	Below 1 Ω
A46-3 (SGB) - K59-15 (SGB2)	Always	Below 1 Ω
A46-1 (SGFL) or K59-25 (SGS2) - Body ground	Always	10 kΩ or higher
A46-2 (SGG) or K59-24 (SGG2) - Body ground	Always	10 kΩ or higher
A46-3 (SGB) or K59-15 (SGB2) - Body ground	Always	10 kΩ or higher

REPLACE ABSORBER CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

FR Damping Force Control Actuator Circuit (C1731-C1734)

DESCRIPTION

The absorber control actuator changes the damping force depending on absorber control ECU signals.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1731	FR Damping Force Control Actuator Circuit	Either condition is met: An open circuit is detected between the front absorber control actuator RH (front shock absorber assembly RH) and absorber control ECU. A short circuit is detected between the front absorber control actuator RH (front shock absorber assembly RH) and absorber control ECU.	Front absorber control actuator RH (front shock absorber assembly RH) Front skid control sensor wire RH Wire harness or connector Absorber control ECU	Does not come on	Yes
C1732	FL Damping Force Control Actuator Circuit	Either condition is met: An open circuit is detected between the front absorber control actuator LH (front shock absorber assembly LH) and absorber control ECU. A short circuit is detected between the front absorber control actuator LH (front shock absorber assembly LH) and absorber control ECU.	Front absorber control actuator LH (front shock absorber assembly LH) Front skid control sensor wire LH Wire harness or connector Absorber control ECU	Does not come on	Yes
C1733	RR Damping Force Control Actuator Circuit	Either condition is met: An open circuit is detected between the rear absorber control actuator RH (rear shock absorber assembly RH) and absorber control ECU. A short circuit is detected between the rear absorber control actuator RH (rear shock absorber assembly RH) and absorber control ECU.	Rear absorber control actuator RH (rear shock absorber assembly RH) Skid control sensor wire RH (No. 1 parking brake wire assembly) Wire harness or connector Absorber control ECU	Does not come on	Yes
C1734	RL Damping Force Control Actuator Circuit	Either condition is met: An open circuit is detected between the rear absorber control actuator LH (rear shock absorber assembly LH) and absorber control ECU. A short circuit is detected between the rear absorber control actuator LH (rear shock absorber assembly LH) and absorber control ECU.	Rear absorber control actuator LH (rear shock absorber assembly LH) Skid control sensor wire LH (No. 2 parking brake wire assembly) Wire harness or connector Absorber control ECU	Does not come on	Yes

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.
Click here
Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
  Click here
- DTC inspection.
  Click here
- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here

PROCEDURE

1.	CLEAR DTCS

(a) Clear the DTCs.

Click here

Chassis > Air suspension > Clear DTCs

2.	PERFORM ACTIVE TEST USING TECHSTREAM (FOUR-WHEEL DAMPING FORCE FULL HARD/SOFT)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension /Active Test.

Chassis > Air suspension > Active Test

Tester Display	Measurement Item	Restrict Condition
Four-Wheel Damping Force Full Hard	Four-wheel damper step fixed at full hard	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal
Four-Wheel Damping Force Full Soft	Four-wheel damper step fixed at full soft	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal

Chassis > Air suspension > Active Test

Tester Display
Four-Wheel Damping Force Full Hard

Chassis > Air suspension > Active Test

Tester Display
Four-Wheel Damping Force Full Soft

(f) When performing the Active Test, read each Tester Display item for the applicable wheel on the Data List and check the operation status of the absorber control actuator for the applicable wheel.

Chassis > Air suspension > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
FR Solenoid Aim Electric Current Level for Control	Target solenoid current value (front wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FL Solenoid Aim Electric Current Level for Control	Target solenoid current value (front wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RR Solenoid Aim Electric Current Level for Control	Target solenoid current value (rear wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RL Solenoid Aim Electric Current Level for Control	Target solenoid current value (rear wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FR Solenoid Drive Duty	Solenoid drive duty value (front wheel RH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
FL Solenoid Drive Duty	Solenoid drive duty value (front wheel LH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
RR Solenoid Drive Duty	Solenoid drive duty value (rear wheel RH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
RL Solenoid Drive Duty	Solenoid drive duty value (rear wheel LH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
FR Solenoid Electric Current	Solenoid current value (front wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FL Solenoid Electric Current	Solenoid current value (front wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RR Solenoid Electric Current	Solenoid current value (rear wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RL Solenoid Electric Current	Solenoid current value (rear wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-

Chassis > Air suspension > Data List

Tester Display
FR Solenoid Aim Electric Current Level for Control
FL Solenoid Aim Electric Current Level for Control
RR Solenoid Aim Electric Current Level for Control
RL Solenoid Aim Electric Current Level for Control
FR Solenoid Drive Duty
FL Solenoid Drive Duty
RR Solenoid Drive Duty
RL Solenoid Drive Duty
FR Solenoid Electric Current
FL Solenoid Electric Current
RR Solenoid Electric Current
RL Solenoid Electric Current

OK:

The Data List step numbers, drive duty values and current values change according to the operation of the Active Test.

GO TO STEP 4

3.	RECONFIRM DTC

(a) Check that the same DTC is output.

Click here

Chassis > Air suspension > Trouble Codes

Result	Proceed to
DTC is output	A
DTC is not output	B

USE SIMULATION METHOD TO CHECK

4.	INSPECT ABSORBER CONTROL ACTUATOR (SHOCK ABSORBER ASSEMBLY)

(a) Turn the engine switch off.

(b) Inspect the absorber control actuator (shock absorber assembly).

for Front Side: Click here

for Rear Side: Click here

Result	Proceed to
OK (for Front Side)	A
OK (for Rear Side)	B
NG (Front absorber control actuator RH (front shock absorber assembly RH) malfunction)	C
NG (Front absorber control actuator LH (front shock absorber assembly LH) malfunction)	D
NG (Rear absorber control actuator RH (rear shock absorber assembly RH) malfunction)	E
NG (Rear absorber control actuator LH (rear shock absorber assembly LH) malfunction)	F

GO TO STEP 7

REPLACE FRONT ABSORBER CONTROL ACTUATOR RH (FRONT SHOCK ABSORBER ASSEMBLY RH)

REPLACE FRONT ABSORBER CONTROL ACTUATOR LH (FRONT SHOCK ABSORBER ASSEMBLY LH)

REPLACE REAR ABSORBER CONTROL ACTUATOR RH (REAR SHOCK ABSORBER ASSEMBLY RH)

REPLACE REAR ABSORBER CONTROL ACTUATOR LH (REAR SHOCK ABSORBER ASSEMBLY LH)

5.	INSPECT FRONT SKID CONTROL SENSOR WIRE

(a) Disconnect the z14 or z13 front skid control sensor wire connector.

(b) Disconnect the A58 or A60 front skid control sensor wire connector.

*A	for RH	*B	for LH
*a	Component without harness connected (Front Skid Control Sensor Wire)	-	-

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
z14-2 - A58-2 (FAR+)	Always	Below 1 Ω
z14-1 - A58-1 (FAR-)	Always	Below 1 Ω
z14-2 or A58-2 (FAR+) - Body ground and other terminals	Always	10 kΩ or higher
z14-1 or A58-1 (FAR-) - Body ground and other terminals	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
z13-2 - A60-2 (FAL+)	Always	Below 1 Ω
z13-1 - A60-1 (FAL-)	Always	Below 1 Ω
z13-2 or A60-2 (FAL+) - Body ground and other terminals	Always	10 kΩ or higher
z13-1 or A60-1 (FAL-) - Body ground and other terminals	Always	10 kΩ or higher

Result	Proceed to
OK	A
NG (for RH)	B
NG (for LH)	C

REPLACE FRONT SKID CONTROL SENSOR WIRE RH

REPLACE FRONT SKID CONTROL SENSOR WIRE LH

6.	CHECK HARNESS AND CONNECTOR (FRONT SKID CONTROL SENSOR WIRE - ABSORBER CONTROL ECU)

(a) Disconnect the K59 absorber control ECU connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
A58-2 (FAR+) - K59-5 (FAR+)	Always	Below 1 Ω
A58-1 (FAR-) - K59-6 (FAR-)	Always	Below 1 Ω
A58-2 (FAR+) or K59-5 (FAR+) - Body ground and other terminals	Always	10 kΩ or higher
A58-1 (FAR-) or K59-6 (FAR-) - Body ground and other terminals	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
A60-2 (FAL+) - K59-2 (FAL+)	Always	Below 1 Ω
A60-1 (FAL-) - K59-3 (FAL-)	Always	Below 1 Ω
A60-2 (FAL+) or K59-2 (FAL+) - Body ground and other terminals	Always	10 kΩ or higher
A60-1 (FAL-) or K59-3 (FAL-) - Body ground and other terminals	Always	10 kΩ or higher

REPLACE ABSORBER CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	INSPECT SKID CONTROL SENSOR WIRE (PARKING BRAKE WIRE ASSEMBLY)

(a) Disconnect the Y6 or Y3 skid control sensor wire (parking brake wire assembly) connector.

(b) Disconnect the YK3 or YK4 skid control sensor wire (parking brake wire assembly) connector.

*A	for RH	*B	for LH
*a	Component without harness connected (Skid Control Sensor Wire (Parking Brake Wire Assembly))	-	-

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
Y6-1 - YK3-3	Always	Below 1 Ω
Y6-3 - YK3-4	Always	Below 1 Ω
Y6-1 or YK3-3 - Body ground and other terminals	Always	10 kΩ or higher
Y6-3 or YK3-4 - Body ground and other terminals	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
Y3-1 - YK4-3	Always	Below 1 Ω
Y3-3 - YK4-4	Always	Below 1 Ω
Y3-1 or YK4-3 - Body ground and other terminals	Always	10 kΩ or higher
Y3-3 or YK4-4 - Body ground and other terminals	Always	10 kΩ or higher

Result	Proceed to
OK	A
NG (for RH)	B
NG (for LH)	C

REPLACE SKID CONTROL SENSOR WIRE RH (NO. 1 PARKING BRAKE WIRE ASSEMBLY)

REPLACE SKID CONTROL SENSOR WIRE LH (NO. 2 PARKING BRAKE WIRE ASSEMBLY)

8.	CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE (PARKING BRAKE WIRE ASSEMBLY) - ABSORBER CONTROL ECU)

(a) Disconnect the K60 absorber control ECU connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

for RH

Tester Connection	Condition	Specified Condition
YK3-3 - K60-6 (RAR+)	Always	Below 1 Ω
YK3-4 - K60-5 (RAR-)	Always	Below 1 Ω
YK3-3 or K60-6 (RAR+) - Body ground and other terminals	Always	10 kΩ or higher
YK3-4 or K60-5 (RAR-) - Body ground and other terminals	Always	10 kΩ or higher

for LH

Tester Connection	Condition	Specified Condition
YK4-3 - K60-2 (RAL+)	Always	Below 1 Ω
YK4-4 - K60-1 (RAL-)	Always	Below 1 Ω
YK4-3 or K60-2 (RAL+) - Body ground and other terminals	Always	10 kΩ or higher
YK4-4 or K60-1 (RAL-) - Body ground and other terminals	Always	10 kΩ or higher

REPLACE ABSORBER CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

Suspension Control ECU Malfunction (C1781)

DESCRIPTION

If a malfunction in the absorber control ECU is detected, DTC C1781 is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

C1781

Suspension Control ECU Malfunction

One of the following conditions is met:

A nonvolatile memory write or read error occurs.
A CAN communication register is stuck.
An overheat protection function malfunction occurs.

Absorber control ECU
CAN communication system

Does not come on

Yes

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.
Click here
Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
  Click here
- DTC inspection.
  Click here
- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here

PROCEDURE

1.	CHECK FOR DTCS (CAN COMMUNICATION SYSTEM)

(a) Check for DTCs.

Click here

Chassis > Air suspension > Trouble Codes

Result	Proceed to
CAN DTCs are not output	A
CAN DTCs are output	B

REPLACE ABSORBER CONTROL ECU

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

Low Battery Positive Voltage (C1782)

DESCRIPTION

This DTC (C1782) is output if voltage matching the DTC detection condition continues to be supplied to the IGB terminal of the absorber control ECU due to malfunctions in the power source or charging circuits, such as the battery or generator assembly circuits.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1782	Low Battery Positive Voltage	While the engine switch is on (IG), the voltage at terminal IGB is 10 V or less, or 16 V or more for 0.5 seconds.	AVS fuse IG1 NO. 3 relay Battery Charging system Wire harness or connector Absorber control ECU	Does not come on	No

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
  Click here
- DTC inspection.
  Click here
- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here
Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.	READ VALUE USING TECHSTREAM (IG POWER SOURCE VOLTAGE)

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Data List.

Chassis > Air suspension > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

IG Power Source Voltage

ECU power supply voltage

Min.: 0.0 V

Max.: 25.5 V

11 to 14 V (Actual ECU power supply voltage): Engine switch on (IG)

Chassis > Air suspension > Data List

Tester Display
IG Power Source Voltage

OK:

The value is as specified in the normal condition column.

GO TO STEP 3

2.	CHECK FOR DTCS

(a) Clear the DTCs.

Click here

Chassis > Air suspension > Clear DTCs

(b) Turn the engine switch off.

Click here

Chassis > Air suspension > Trouble Codes

Result	Proceed to
DTC is not output	A
DTC is output	B

USE SIMULATION METHOD TO CHECK

REPLACE ABSORBER CONTROL ECU

3.	INSPECT BATTERY

(a) Check the battery voltage.

Standard Voltage:

11 to 14 V

CHECK OR REPLACE CHARGING SYSTEM OR BATTERY

4.	INSPECT IG1 NO. 3 RELAY

(a) Turn the engine switch off.

(b) Inspect the IG1 NO. 3 relay.

Click here

REPLACE IG1 NO. 3 RELAY

5.	CHECK HARNESS AND CONNECTOR (POWER SOURCE - IG1 NO. 3 RELAY)

(a) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

Tester Connection	Condition	Specified Condition
1 (IG1 NO. 3 relay) - Body ground	Engine switch on (IG)	11 to 14 V
5 (IG1 NO. 3 relay) - Body ground	Always	11 to 14 V

CHECK OR REPLACE CHARGING SYSTEM OR BATTERY

6.	CHECK HARNESS AND CONNECTOR (IG1 NO. 3 RELAY - ABSORBER CONTROL ECU AND BODY GROUND)

(a) Disconnect the K59 absorber control ECU connector.

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 (IG1 NO. 3 relay) - K59-1 (IGB)	Always	Below 1 Ω
3 (IG1 NO. 3 relay) or K59-1 (IGB) - Body ground	Always	10 kΩ or higher
2 (IG1 NO. 3 relay) - Body ground	Always	Below 1 Ω

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.	CHECK HARNESS AND CONNECTOR (ABSORBER CONTROL ECU - BODY GROUND)

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection	Condition	Specified Condition
K59-4 (GND) - Body ground	Always	Below 1 Ω

REPLACE ABSORBER CONTROL ECU

REPAIR OR REPLACE HARNESS OR CONNECTOR

Front Wheels Speed Sensor Signal Malfunction (C1783)

DESCRIPTION

The speed sensors monitor the speed of the wheels and send an appropriate speed signal to the absorber control ECU through the skid control ECU (brake actuator assembly).

If a malfunction occurs in either a front speed sensor or rear speed sensor, DTC C1783 is stored.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1783	Front Wheels Speed Sensor Signal Malfunction	A speed sensor malfunction signal from the skid control ECU (brake actuator assembly) is detected for 1 second or more.	Electronically controlled brake system	Does not come on	Yes

PROCEDURE

1.	GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

(a) Go to electronically controlled brake system.

Click here

END

Steering Sensor Signal Malfunction (C1784)

DESCRIPTION

Steering sensor signals are sent to the absorber control ECU via CAN communication.

If a communication error is detected, DTC C1784 is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

C1784

Steering Sensor Signal Malfunction

A steering sensor communication error is detected, or a steering sensor power malfunction is detected for 5 seconds or more.

Electronically controlled brake system

Does not come on

Yes

(Under some of the detection conditions (sensor power +B open malfunction is detected), DTC is not stored.)

PROCEDURE

1.	GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

(a) Go to electronically controlled brake system.

Click here

END

Master Cylinder Pressure Circuit (C1786)

DESCRIPTION

The absorber control ECU stores this DTC when a malfunction signal from the master cylinder pressure sensor built into the brake actuator assembly is received via CAN communication.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1786	Master Cylinder Pressure Circuit	A master cylinder pressure sensor malfunction signal is continuously received from the skid control ECU (brake actuator assembly) for 3 seconds or more.	Electronically controlled brake system	Does not come on	Yes

PROCEDURE

1.	GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

(a) Go to electronically controlled brake system.

Click here

END

(Horizontality) G Sensor Malfunction (C1787)

DESCRIPTION

The absorber control ECU receives a signal from the yaw rate and acceleration sensor (airbag ECU assembly) via CAN communication.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
C1787	(Horizontality) G Sensor Malfunction	While the engine switch is on (IG), yaw rate and acceleration sensor (airbag ECU assembly) malfunction signal is detected for 1 second or more.	Electronically controlled brake system	Does not come on	Yes

PROCEDURE

1.	GO TO ELECTRONICALLY CONTROLLED BRAKE SYSTEM

(a) Go to electronically controlled brake system.

Click here

END

Vehicle Identification Malfunction (C1789)

DESCRIPTION

When the absorber control ECU has not acquired the vehicle identification information, DTC C1789 is stored. When the vehicle identification information is correctly acquired, this DTC is cleared. Vehicle identification information is automatically acquired when the system enters test mode.

If an incorrect ECM is installed, the vehicle information will not match and DTC C1789 will be stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

C1789

Vehicle Identification Malfunction

One of the following conditions is met:

The vehicle identification information is not stored.
Vehicle identification information that is different from the stored information is received 3 times.

Vehicle identification information
ECM
CAN communication system
Absorber control ECU

Does not come on

Yes

(Under some of the detection conditions (control map non-retrieval is not stored), DTC is not stored.)

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.
Click here
Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
  Click here
- DTC inspection.
  Click here
- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here

PROCEDURE

1.	CHECK FOR DTCS

(a) Check for DTCs.

Click here

Chassis > Air suspension > Trouble Codes

HINT:

If DTC C1781 (Suspension Control ECU Malfunction) is output at the same time, perform troubleshooting for C1781 first.

Result	Proceed to
C1781 and CAN communication malfunction DTC are not output	A
C1781 is output	B
CAN communication DTC is output	C

GO TO C1781

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

2.	CHECK VEHICLE IDENTIFICATION INFORMATION STATUS

(a) Check that vehicle identification information has been stored.

Click here

Result	Proceed to
Information stored	A
Information not stored	B

PERFORM VEHICLE IDENTIFICATION INFORMATION REGISTRATION

3.	CHECK RELATED PART

(a) If the DTC was output as a result of the replacement of a related part, replace the part with one that has a correct part number.

Related Part

ECM

NOTICE:

When removing a related part to check it, be sure to follow the appropriate procedures and precautions.

Refer to the following procedures to remove the ECM.

Click here

HINT:

If parts have not been replaced and DTC C1789 is output, there may be an internal malfunction in the absorber control ECU. Therefore, replace the absorber control ECU.

Result	Proceed to
The related part has an incorrect part number	A
The related part has the correct part number, or a related part and absorber control ECU have not been replaced	B

REPLACE RELATED PART WITH PART THAT HAS CORRECT PART NUMBER

REPLACE ABSORBER CONTROL ECU

Customize Parameters

CUSTOMIZE PARAMETERS

CUSTOMIZE ADAPTIVE VARIABLE SUSPENSION SYSTEM

HINT:

"Custom" mode can be selected by using the drive mode select switch (electric parking brake switch assembly).

(a) Customizing with the multi-display

(1) Turn the engine switch on (IG).

(2) Enter the following menus: MENU / Setup / Vehicle / Vehicle Customization / Drive Mode Customization.

(3) Select the setting by referring to the table below.

Display	Content	Default	Setting
Powertrain	Acceleration response, etc.	Normal	Power / Normal / Eco
Chassis	Damping force of suspension, steering assist force, etc.	Normal	Sport / Normal
Climate	Effectiveness of air conditioning system, etc.	Normal	Normal / Eco

Data List / Active Test

DATA LIST / ACTIVE TEST

READ DATA LIST

NOTICE:

In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not.

HINT:

Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be discovered before parts or wiring is disturbed. Reading the Data List information early in troubleshooting is one way to save diagnostic time.

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Data List.

(f) Read the Data List according to the display on the Techstream.

Chassis > Air suspension > Data List

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
(Up&Down)G Sensor FR	Front acceleration sensor RH (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (front RH) is bounced.
(Up&Down)G Sensor FL	Front acceleration sensor LH (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (front LH) is bounced.
(Up&Down)G Sensor Rear	Rear acceleration sensor (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (rear) is bounced.
Gravity Sensor(Side to Side)	Lateral acceleration sensor (side to side)	Min.: -1176.37 m/s2 Max.: 1176.33 m/s2	Changes depending on acceleration generated when turning	-
Stop Light Switch	Stop light switch	OFF or ON	OFF: Brake pedal released ON: Brake pedal depressed	-
SPORT Switch	Drive mode select switch	OFF or ON	OFF: Not in Sport S+ mode or Custom mode (when the Chassis item is set to SPORT) ON: During Sport S+ mode or Custom mode (when the Chassis item is set to SPORT)	-
HV Ready	HV ready status	OFF or ON	OFF: Always	This item is displayed on the Techstream but is not required for diagnosis or repair.
TC Terminal	TC terminal status	OFF or ON	OFF: DTC not output ON: DTC output	-
TS Terminal	TS terminal status	OFF or ON	OFF: During normal mode ON: During test mode	-
IG Power Source Voltage	ECU power supply voltage	Min.: 0.0 V Max.: 25.5 V	11 to 14 V (Actual ECU power supply voltage): Engine switch on (IG)	-
Steering Angle	Steering angle sensor reading	Min.: -49152.0 deg Max.: 49150.5 deg	Actual steering angle Steering wheel turned left: Reading increases Steering wheel turned right: Reading decreases	-
Engine Speed	Engine speed	Min.: 0 rpm Max.: 25500 rpm	Actual engine speed	-
FR Wheel Speed	Front speed sensor RH reading	Min.: 0 km/h (0 mph) Max.: 255 km/h (159 mph)	Actual vehicle speed	No large fluctuations when driving at a constant speed.
FL Wheel Speed	Front speed sensor LH reading	Min.: 0 km/h (0 mph) Max.: 255 km/h (159 mph)	Actual vehicle speed	No large fluctuations when driving at a constant speed.
RR Wheel Speed	Rear speed sensor RH reading	Min.: 0 km/h (0 mph) Max.: 255 km/h (159 mph)	Actual vehicle speed	No large fluctuations when driving at a constant speed.
RL Wheel Speed	Rear speed sensor LH reading	Min.: 0 km/h (0 mph) Max.: 255 km/h (159 mph)	Actual vehicle speed	No large fluctuations when driving at a constant speed.
Driving Torque	Driving torque	Min.: -1024 Nm Max.: 1023 Nm	Changes in accordance with accelerator pedal position	-
Adaptive Variable Suspension(AVS) Mode	Adaptive variable suspension system (AVS) mode	NORMAL, COMFORT, SEMI CO, SEMI SP or SPORTS	NORMAL: Not in Sport S+ mode or Custom mode (when the Chassis item is set to SPORT) SPORTS: During Sport S+ mode or Custom mode (when the Chassis item is set to SPORT)	-
Compatible Constant Information	Information used to change the compatible constant	Min.: 0 Max.: 255	-	-
Identical Constant Information	Information used to change the identical constant	Min.: 0 Max.: 255	-	-
Design Constant Information	Information used to change the design constant	Min.: 0 Max.: 255	-	-
AVS Control Information FR	AVS control information (front wheel RH)	Min.: 0 Max.: 255	-	-
AVS Control Information FL	AVS control information (front wheel LH)	Min.: 0 Max.: 255	-	-
AVS Control Information RR	AVS control information (rear wheel RH)	Min.: 0 Max.: 255	-	-
AVS Control Information RL	AVS control information (rear wheel LH)	Min.: 0 Max.: 255	-	-
Vehicle Information (Conv/HV)	Vehicle identification information (hybrid vehicle or except hybrid vehicle)	Unknown, Conv or HV	Conv: When vehicle identification normal	-
Stop and Start Learning Status	Learning status of stop and start setting availability after vehicle identification information registration is performed	Unset, OFF or ON	OFF	-
Overheat Protection Control Count	Number of times overheat protection was performed in past	Min.: 0 Max.: 255	Displays number of times overheat protection was performed in past	-
ECU Substrate Maximum Temperature	Stored ECU substrate maximum temperature	Min.: 40°C Max.: 120°C	Displays maximum temperature of ECU substrate in past	-
Status of Overheat Protection Control	Current overheat protection status	OFF or ON	OFF: No overheat protection	ON: When overheat protection is on, damping force control stops until the temperature drops below a certain value.
G Sensor Voltage	G sensor power supply voltage	Min.: 0.0 V Max.: 25.5 V	4.8 to 5.2 V	-
ECU Substrate Temperature	Current ECU substrate temperature	Min.: 40°C Max.: 120°C	Displays current ECU substrate temperature	-
FR Solenoid Aim Electric Current Level for Control	Target solenoid current value (front wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FL Solenoid Aim Electric Current Level for Control	Target solenoid current value (front wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RR Solenoid Aim Electric Current Level for Control	Target solenoid current value (rear wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RL Solenoid Aim Electric Current Level for Control	Target solenoid current value (rear wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FR Solenoid Drive Duty	Solenoid drive duty value (front wheel RH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
FL Solenoid Drive Duty	Solenoid drive duty value (front wheel LH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
RR Solenoid Drive Duty	Solenoid drive duty value (rear wheel RH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
RL Solenoid Drive Duty	Solenoid drive duty value (rear wheel LH)	Min.: 0% Max.: 100%	Changes depending on target damping force	-
FR Solenoid Electric Current	Solenoid current value (front wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FL Solenoid Electric Current	Solenoid current value (front wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RR Solenoid Electric Current	Solenoid current value (rear wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RL Solenoid Electric Current	Solenoid current value (rear wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
Air suspension Learning Status	Learning status of air suspension system setting availability after vehicle identification information registration is performed	Unset, OFF or ON	OFF	-
Number of Trouble Codes	Number of DTCs stored	Min.: 0 Max.: 255	0	-

PERFORM ACTIVE TEST

HINT:

Using the Techstream to perform Active Tests allows relays, VSVs, actuators and other items to be operated without removing any parts. This non-intrusive functional inspection can be very useful because intermittent operation may be discovered before parts or wiring is disturbed. Performing Active Tests early in troubleshooting is one way to save diagnosis time. Data List information can be displayed while performing Active Tests.

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Active Test.

(f) Perform the Active Test according to the display on the Techstream.

Chassis > Air suspension > Active Test

Tester Display	Measurement Item	Restrict Condition
Four-Wheel Damping Force Full Hard	Four-wheel damping force fixed at full hard	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal
Four-Wheel Damping Force Full Soft	Four-wheel damper step fixed at full soft	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal
Damper Step FR (Electric Current)	Changes damping force (front RH)	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal
Damper Step FL (Electric Current)	Changes damping force (front LH)	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal
Damper Step RR (Electric Current)	Changes damping force (rear RH)	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal
Damper Step RL (Electric Current)	Changes damping force (rear LH)	Vehicle stopped Engine idling When the absorber control actuator is normal When the power source voltage is normal

Diagnosis System

DIAGNOSIS SYSTEM

DIAGNOSIS SYSTEM

(a) DTCs (normal mode)

(1) DTCs are stored in the absorber control ECU and output by using the Techstream. Refer to the DTC check procedure.

Click here

(b) Test mode

(1) By switching from normal mode to test mode, it is possible to inspect the front acceleration sensor and rear acceleration sensor.

Click here

Diagnostic Trouble Code Chart

DIAGNOSTIC TROUBLE CODE CHART

Adaptive Variable Suspension System

DTC No.	Detection Item	Warning Indicate	Memory
C1715	Front Acceleration Sensor RH Malfunction	Does not come on	Yes
C1716	Front Acceleration Sensor LH Malfunction	Does not come on	Yes
C1717	Rear Acceleration Sensor Malfunction	Does not come on	Yes
C1731	FR Damping Force Control Actuator Circuit	Does not come on	Yes
C1732	FL Damping Force Control Actuator Circuit	Does not come on	Yes
C1733	RR Damping Force Control Actuator Circuit	Does not come on	Yes
C1734	RL Damping Force Control Actuator Circuit	Does not come on	Yes
C1781	Suspension Control ECU Malfunction	Does not come on	Yes
C1782	Low Battery Positive Voltage	Does not come on	No
C1783	Front Wheels Speed Sensor Signal Malfunction	Does not come on	Yes
C1784	Steering Sensor Signal Malfunction	Does not come on	Yes (Under some of the detection conditions (sensor power +B open malfunction is detected), DTC is not stored.)
C1786	Master Cylinder Pressure Circuit	Does not come on	Yes
C1787	(Horizontality) G Sensor Malfunction	Does not come on	Yes
C1789	Vehicle Identification Malfunction	Does not come on	Yes (Under some of the detection conditions (control map non-retrieval is not stored), DTC is not stored.)
C1796	(Up&Down)G Sensor FR	Test mode	(Test mode)
C1797	(Up&Down)G Sensor FL	Test mode	(Test mode)
C1798	(Up&Down)G Sensor Rear	Test mode	(Test mode)
U0100	Lost Communication With ECM/PCM "A"	Does not come on	Yes
U0101	Lost Communication with TCM	Does not come on	Yes
U0122	Lost Communication With Vehicle Dynamics Control Module	Does not come on	Yes
U0124	Lost Communication with Lateral Acceleration Sensor Module	Does not come on	Yes
U0126	Lost Communication with Steering Angle Sensor Module	Does not come on	Yes

Dtc Check / Clear

DTC CHECK / CLEAR

CHECK FOR DTC

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Trouble Codes.

Chassis > Air suspension > Trouble Codes

HINT:

When freeze frame data is stored, check the freeze frame data.

Click here

(f) Read the DTCs by following the prompts on the Techstream screen.

HINT:

Refer to the Techstream operator's manual for further details.

(g) Refer to Diagnostic Trouble Code Chart for DTC information.

Click here

CLEAR DTC

HINT:

After repairing the malfunctions, clear the DTCs.

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Trouble Codes.

Chassis > Air suspension > Clear DTCs

NOTICE:

DTCs and freeze frame data are cleared at the same time.

(f) Clear the DTCs by following the prompts on the Techstream screen.

HINT:

Refer to the Techstream operator's manual for further details.

Fail-safe Chart

FAIL-SAFE CHART

FAIL-SAFE CHART

Adaptive Variable Suspension System

DTC Chart	Malfunction Item	Fail-safe Operation
C1715 C1716 C1717	Acceleration sensor circuit	Partial control continues.
C1731 C1732 C1733 C1734	Absorber control actuator circuit	Control stops.
C1781	Absorber control ECU	Control stops.
C1782	Power source voltage	Control stops.
C1783	Vehicle speed sensor circuit	Control stops.
C1784	Steering angle sensor	Partial control continues.
C1786	Master cylinder pressure circuit	Partial control continues.
C1787	G sensor (Yaw rate sensor)	Partial control continues.
C1789	Vehicle identification malfunction	Control stops.
U0100	CAN communication system	Partial control continues.
U0101	CAN communication system	Partial control continues.
U0122	CAN communication system	Partial control continues.
U0124	CAN communication system	Partial control continues.
U0126	CAN communication system	Partial control continues.

Freeze Frame Data

FREEZE FRAME DATA

FREEZE FRAME DATA

(a) The absorber control ECU stores system condition information as freeze frame data the moment a DTC is stored. The Freeze Frame Data can be displayed using the Techstream.

(b) Freeze frame data when a DTC is stored.

(1) Freeze frame data is stored the moment a DTC is stored.

(2) When freeze frame data is stored when a DTC is stored, the data is not updated or deleted until DTCs are cleared.

CHECK FREEZE FRAME DATA

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Trouble Codes.

Chassis > Air suspension > Trouble Codes

(f) Select a DTC to display the freeze frame data.

(g) Check the freeze frame data for the output DTC.

Chassis > Air suspension

Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
(Up&Down)G Sensor FR	Front acceleration sensor RH (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (front RH) is bounced.
(Up&Down)G Sensor FL	Front acceleration sensor LH (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (front LH) is bounced.
(Up&Down)G Sensor Rear	Rear acceleration sensor (up and down)	Min.: -1045.29 m/s2 Max.: 1045.26 m/s2	-0.98 to 0.98 m/s2 when stationary	The value changes when the vehicle (rear) is bounced.
IG Power Source Voltage	ECU power supply voltage	Min.: 0.0 V Max.: 25.5 V	11 to 14 V (Actual ECU power supply voltage): Engine switch on (IG)	-
G Sensor Voltage	G sensor power supply voltage	Min.: 0.0 V Max.: 25.5 V	4.8 to 5.2 V	-
ECU Substrate Temperature	Current ECU substrate temperature	Min.: 40°C Max.: 120°C	Displays current ECU substrate temperature	-
FR Solenoid Aim Electric Current Level for Control	Target solenoid current value (front wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FL Solenoid Aim Electric Current Level for Control	Target solenoid current value (front wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RR Solenoid Aim Electric Current Level for Control	Target solenoid current value (rear wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RL Solenoid Aim Electric Current Level for Control	Target solenoid current value (rear wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FR Solenoid Electric Current	Solenoid current value (front wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
FL Solenoid Electric Current	Solenoid current value (front wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RR Solenoid Electric Current	Solenoid current value (rear wheel RH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
RL Solenoid Electric Current	Solenoid current value (rear wheel LH)	Min.: 0 mA Max.: 2040 mA	Changes depending on target damping force	-
Number of Trouble Codes	Number of DTCs stored	Min.: 0 Max.: 255	0	-

How To Proceed With Troubleshooting

CAUTION / NOTICE / HINT

HINT:

Use the following procedure to troubleshoot the adaptive variable suspension system.
*: Use the Techstream.

PROCEDURE

1.	VEHICLE BROUGHT TO WORKSHOP

2.	PROBLEM SYMPTOM CONFIRMATION

3.	INSPECT BATTERY VOLTAGE

(a) Measure the voltage of the battery.

Standard Voltage:

11 to 14 V

If the voltage is below 11 V, recharge or replace the battery before proceeding.

4.	CHECK ECUS CONNECTED TO CAN BUS*

(a) Check the ECUs connected to the CAN bus.

Click here

Result	Proceed to
No malfunction appears	A
Malfunction appears	B

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

5.	CHECK DTC AND FREEZE FRAME DATA*

(a) Check for and write down any DTCs and Freeze Frame Data.

for DTC Check / Clear: Click here

for Freeze Frame Data: Click here

Chassis > Air suspension > Trouble Codes

(b) Clear the DTCs and Freeze Frame Data.

for DTC Check / Clear: Click here

for Freeze Frame Data: Click here

Chassis > Air suspension > Clear DTCs

Chassis > Air suspension > Trouble Codes

Result	Proceed to
DTCs are not output	A
DTCs are output	B

GO TO STEP 7

6.	OVERALL ANALYSIS AND TROUBLESHOOTING*

(a) Refer to Terminals of ECU.

Click here

(b) Refer to Data List / Active Test.

Click here

GO TO STEP 8

7.	DIAGNOSTIC TROUBLE CODE CHART

(a) Proceed to Diagnostic Trouble Code Chart.

Click here

8.	REPAIR OR REPLACE

9.	CONFIRMATION TEST

END

Parts Location

PARTS LOCATION

ILLUSTRATION

*1	FRONT ABSORBER CONTROL ACTUATOR RH (FRONT SHOCK ABSORBER ASSEMBLY RH)	*2	FRONT ABSORBER CONTROL ACTUATOR LH (FRONT SHOCK ABSORBER ASSEMBLY LH)
*3	REAR ABSORBER CONTROL ACTUATOR RH (REAR SHOCK ABSORBER ASSEMBLY RH)	*4	REAR ABSORBER CONTROL ACTUATOR LH (REAR SHOCK ABSORBER ASSEMBLY LH)
*5	FRONT SKID CONTROL SENSOR WIRE RH	*6	FRONT SKID CONTROL SENSOR WIRE LH
*7	SKID CONTROL SENSOR WIRE RH (NO. 1 PARKING BRAKE WIRE ASSEMBLY)	*8	SKID CONTROL SENSOR WIRE LH (NO. 2 PARKING BRAKE WIRE ASSEMBLY)
*9	ABSORBER CONTROL ECU	*10	SKID CONTROL ECU (BRAKE ACTUATOR ASSEMBLY)
*11	ECM	*12	NO. 2 ENGINE ROOM RELAY BLOCK AND NO. 2 JUNCTION BLOCK ASSEMBLY - IG1 NO. 3 RELAY - AVS FUSE

ILLUSTRATION

*1	DRIVE MODE SELECT SWITCH (ELECTRIC PARKING BRAKE SWITCH ASSEMBLY)	*2	ACCELERATION SENSOR ASSEMBLY RH
*3	ACCELERATION SENSOR ASSEMBLY LH	*4	COMBINATION METER ASSEMBLY
*5	STEERING SENSOR	*6	DLC3
*7	AIRBAG ECU ASSEMBLY	*8	DRIVING SUPPORT ECU ASSEMBLY
*9	INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY - ECU-IG1 NO. 3 FUSE	-	-

Precaution

PRECAUTION

PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL

NOTICE:

When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected.

System Name	See Procedure
Lane Departure Alert System (w/ Steering Control)
Intelligent Clearance Sonar System
Parking Assist Monitor System
Panoramic View Monitor System
Pre-collision System
Lighting System (for Gasoline Model with Cornering Light)

ADAPTIVE VARIABLE SUSPENSION SYSTEM PRECAUTION

NOTICE:

Performing work after replacing the absorber control ECU with a normally functioning one from another vehicle may result in DTCs being stored, or have a negative effect on other systems. When replacing the absorber control ECU, be sure to install a new one.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
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System Description

SYSTEM DESCRIPTION

ADAPTIVE VARIABLE SUSPENSION SYSTEM DESCRIPTION

(a) The ECM judges the mode based on the input from the drive mode select switch (electric parking brake switch assembly). The absorber control ECU receives the judgment result via CAN communication and controls the adaptive variable suspension.

System Diagram

SYSTEM DIAGRAM

Terminals Of Ecu

TERMINALS OF ECU

CHECK ABSORBER CONTROL ECU

(a) Measure the voltage and resistance according to the value(s) in the table below.

NOTICE:

Inspect the connectors from the back side while the connectors are connected.

Terminal No. (Symbol)	Wiring Color	Terminal Description	Condition	Specified Condition
K59-1 (IGB) - K59-4 (GND)	GR - W-B	IG power supply	Engine switch on (IG)	11 to 14 V
K59-4 (GND) - Body ground	W-B - Body ground	Ground	Always	Below 1 Ω
K59-8 (CANH) - K59-7 (CANL)	B - W	CAN communication line	Engine switch off	54 to 69 Ω
K59-14 (SGB1) - K59-4 (GND)	R - W-B	Acceleration sensor RH power source	Engine switch on (IG)	4.75 to 5.25 V
K59-15 (SGB2) - K59-4 (GND)	SB - W-B	Acceleration sensor LH power source	Engine switch on (IG)	4.75 to 5.25 V
K59-22 (SGG1) - K59-4 (GND)	G - W-B	Acceleration sensor RH ground	Always	Below 1 Ω
K59-23 (SGS1) - K59-4 (GND)	L - W-B	Acceleration sensor RH signal input	Engine switch on (IG) with vehicle stationary	2.1 to 2.9 V
K59-24 (SGG2) - K59-4 (GND)	LG - W-B	Acceleration sensor LH ground	Always	Below 1 Ω
K59-25 (SGS2) - K59-4 (GND)	W - W-B	Acceleration sensor LH signal input	Engine switch on (IG) with vehicle stationary	2.1 to 2.9 V

Test Mode Procedure

TEST MODE PROCEDURE

TEST MODE PROCEDURE

NOTICE:

After replacing the absorber control ECU, it is necessary to perform registration of vehicle identification information. Vehicle identification information is automatically acquired when the system enters test mode.

HINT:

When entering test mode, the absorber control ECU stores all the test mode DTCs first. After completing the check for each test mode item, the test mode DTCs whose deletion conditions are met are cleared. The test mode DTCs for some items may not be cleared when only a certain signal is inspected.
When the system returns to normal mode, all the test mode DTCs will be cleared.

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension / Utility / Signal Check.

Chassis > Air suspension > Utility

Tester Display
Signal Check

(f) Confirm that the system is in test mode by checking that the "Sport S+" indicator in the combination meter assembly is blinking at approximately 0.1-second intervals (0.1 seconds on and 0.1 seconds off).

HINT:

When vehicle identification information has not been acquired, the "Sport S+" indicator in the combination meter assembly blinks at approximately 1-second intervals (1 second on and 1 second off). After vehicle identification information is acquired, the "Sport S+" indicator in the combination meter assembly blinks at approximately 0.1-second intervals (0.1 seconds on and 0.1 seconds off).

(g) With the vehicle stationary on a level surface, wait for 1 second or more.

(h) Read the test mode DTCs by following the prompts on the Techstream screen.

(i) End test mode by following the prompts on the Techstream screen.

(j) Turn the engine switch off and disconnect the Techstream from the DLC3.

TEST MODE DTC CHART

(a) If a trouble code is output during the test mode DTC check, check the circuit listed for that code. For details of each code, refer to Link for the respective DTC in the chart.

DTC Code	Detection Item	Trouble Area	Deletion Condition
C1796	(Up&Down)G Sensor FR	Acceleration sensor assembly RH Wire harness or connector Absorber control ECU	With the vehicle stationary on a level surface, an acceleration sensor value that is within -1.96 to 1.96 m/s2 is received from the acceleration sensor for 1 second or more.
C1797	(Up&Down)G Sensor FL	Acceleration sensor assembly LH Wire harness or connector Absorber control ECU
C1798	(Up&Down)G Sensor Rear	Absorber control ECU

Lost Communication With ECM/PCM "A" (U0100-U0122,U0124,U0126)

DESCRIPTION

The absorber control ECU receives signals from the ECM, skid control ECU (brake actuator assembly), airbag ECU assembly and steering sensor via CAN communication.

When DTCs indicating a CAN communication system malfunction are output, repair the CAN communication system first.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Memory
U0100	Lost Communication With ECM/PCM "A"	While driving at 30 km/h (19 mph) or more, data is not received via CAN communication for 3 seconds or more.	ECM CAN communication system Absorber control ECU	Does not come on	Yes
U0101	Lost Communication with TCM	While driving at 30 km/h (19 mph) or more, data is not received via CAN communication for 6 seconds or more.	ECM CAN communication system Absorber control ECU	Does not come on	Yes
U0122	Lost Communication With Vehicle Dynamics Control Module	Data is not received from the skid control ECU (brake actuator assembly) via CAN communication for 3 seconds or more.	Skid control ECU (brake actuator assembly) CAN communication system Absorber control ECU	Does not come on	Yes
U0124	Lost Communication with Lateral Acceleration Sensor Module	Data is not received from the airbag ECU assembly via CAN communication for 3 seconds or more.	Airbag ECU assembly CAN communication system Absorber control ECU	Does not come on	Yes
U0126	Lost Communication with Steering Angle Sensor Module	Data is not received from the steering sensor via CAN communication for 3 seconds or more.	Steering sensor CAN communication system Absorber control ECU	Does not come on	Yes

CAUTION / NOTICE / HINT

NOTICE:

Before performing troubleshooting, inspect the connectors of related circuits.
If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.
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Before replacing the absorber control ECU, perform all of the following:
- Symptom simulation.
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- DTC inspection.
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- Techstream inspection.
  Click here
  - If no malfunctions are found in other areas, replace the absorber control ECU.
After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.
Click here

PROCEDURE

1.	CHECK FOR DTCS

(a) Clear the DTCs.

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Chassis > Air suspension > Clear DTCs

(b) Turn the engine switch off.

(d) Check for DTCs.

Click here

Chassis > Air suspension > Trouble Codes

Result	Proceed to
CAN DTCs are not output	A
CAN DTCs are output	B

HINT:

If a CAN communication malfunction DTC and a related sensor malfunction DTC are output at the same time, the CAN communication malfunction must be repaired before troubleshooting the sensor.

USE SIMULATION METHOD TO CHECK

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

Absorber Control Switch

Front Acceleration Sensor

See More:

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual > Electronically Controlled Brake System(for Hv Model): Freeze Frame Data
FREEZE FRAME DATA FREEZE FRAME DATA/INFORMATION (a) Using the Techstream, check the vehicle condition (ECU, sensor) when the brake system operates or a DTC is output. (b) The Freeze Frame Data that is recorded when a DTC is stored can be used to check the INF codes, but only for DTCs which can be st ...