Toyota Avalon Service & Repair Manual: Front Vertical Sensor Malfunction (B2652)

DESCRIPTION

When the position control ECU assembly does not receive a front vertical motor position sensor signal despite the seat having been moved upward or downward by power seat motor operation, this DTC is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B2652

Front Vertical Sensor Malfunction

Front vertical motor position sensor signal not received when power seat moved upward or downward

  • Position control ECU assembly
  • Front vertical motor (separate type front seat cushion spring assembly LH)
  • Wire harness or connector

WIRING DIAGRAM

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Body Electrical > Driver Seat > Clear DTCs
NEXT

2.

CHECK FOR DTC

(a) Check for DTCs.

Body Electrical > Driver Seat > Trouble Codes

OK:

DTC B2652 is not output.

OK

USE SIMULATION METHOD TO CHECK

NG

3.

PERFORM ACTIVE TEST USING TECHSTREAM (SEAT FRONT VERTICAL OPERATION)

(a) Connect the Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Driver Seat / Active Test.

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

Body Electrical > Driver Seat > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Front Vertical Operation

Seat front vertical operation

OFF/Down/Up

-

Body Electrical > Driver Seat > Active Test

Tester Display

Front Vertical Operation

OK:

Front vertical motor operates normally.

NG

GO TO STEP 7

OK

4.

CHECK POSITION CONTROL ECU ASSEMBLY (FRONT VERTICAL MOTOR CIRCUIT)

(a) Disconnect the R27 front vertical motor (separate type front seat cushion spring assembly LH) connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

R27-4 (SSFV) - R27-2 (SENG)

Front vertical switch on

4.8 to 5.1 V

NG

GO TO STEP 6

OK

5.

CHECK FRONT VERTICAL MOTOR (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY LH)

(a) Reconnect the R27 front vertical motor (separate type front seat cushion spring assembly LH) connector.

*a

Component with harness connected

(Front Vertical Motor (Separate Type Front Seat Cushion Spring Assembly LH))

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

R27-4 (SSFV) - Body ground

Front vertical motor operating

4.5 to 4.8 V

OK

REPLACE POSITION CONTROL ECU ASSEMBLY

NG

REPLACE FRONT VERTICAL MOTOR (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY LH)

6.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - FRONT VERTICAL MOTOR (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY LH))

(a) Disconnect the R32 position control ECU assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R32-10 (SSFV) - R27-4 (SSFV)

Always

Below 1 Ω

R32-10 (SSFV) or R27-4 (SSFV) - Body ground

Always

10 kΩ or higher

R32-12 (SENG) - R27-2 (SENG)

Always

Below 1 Ω

R32-12 (SENG) or R27-2 (SENG) - Body ground

Always

10 kΩ or higher

OK

REPLACE POSITION CONTROL ECU ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.

INSPECT FRONT VERTICAL MOTOR (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY LH)

(a) Remove the front vertical motor (separate type front seat cushion spring assembly LH).

Click here

(b) Inspect the front vertical motor (separate type front seat cushion spring assembly LH).

Click here

NG

REPLACE FRONT VERTICAL MOTOR (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY LH)

OK

8.

CHECK HARNESS AND CONNECTOR (POSITION CONTROL ECU ASSEMBLY - FRONT VERTICAL MOTOR (SEPARATE TYPE FRONT SEAT CUSHION SPRING ASSEMBLY LH))

(a) Disconnect the R33 and R30 position control ECU assembly connectors.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

R33-7 (FRV+) - R27-3 (FRV+)

Always

Below 1 Ω

R33-7 (FRV+) or R27-3 (FRV+) - Body ground

Always

10 kΩ or higher

R30-4 (FRV-) - R27-1 (FRV-)

Always

Below 1 Ω

R30-4 (FRV-) or R27-1 (FRV-) - Body ground

Always

10 kΩ or higher

OK

REPLACE POSITION CONTROL ECU ASSEMBLY

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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