Toyota Avalon Service & Repair Manual: Servo Pressure Sensor Zero Point Malfunction (C14C3)

DESCRIPTION

The Servo pressure sensor detects and outputs the brake fluid pressure generated in the wheel cylinder according to the vehicle condition to the skid control ECU (brake booster with master cylinder assembly).

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

MIL

Note

C14C3

Servo Pressure Sensor Zero Point Malfunction

424

When the brake pedal is not depressed, the servo pressure sensor output value is -0.63 MPa (-6.4 kgf/cm2, -91.4 psi) or less or 1.53 MPa (15.6 kgf/cm2, 222 psi) or more for 3 seconds or more.

Skid control ECU (brake booster with master cylinder assembly)

Comes on

  • INF Code 424: SAE Code C14C3
  • Electronically controlled brake system DTC

MONITOR DESCRIPTION

When the brake pedal is not operated and the servo pressure sensor output value exceeds a specific value, or the value is less than a specific value for a certain amount of time, the skid control ECU (brake booster with master cylinder assembly) judges that the zero point of the servo pressure sensor is abnormal and illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs

C14C3: Servo pressure sensor exceeded learning limit

Required Sensors/Components(Main)

Brake actuator (brake booster with master cylinder assembly)

Required Sensors/Components(Related)

Brake pedal stroke sensor assembly

Brake actuator (brake booster with master cylinder assembly)

Stop light switch assembly

Frequency of Operation

Continuous

Duration

3 seconds

MIL Operation

Immediately

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

C0562 (Brake pedal stroke sensor assembly voltage circuit/open)

C124B (Brake pedal stroke sensor assembly invalid data)

C14B0 (Reaction force pressure sensor voltage circuit check)

C14B1 (Reaction force pressure sensor lost communication)

C14B2 (Reaction force pressure sensor internal malfunction)

C14B3 (Reaction force pressure sensor exceeded learning limit)

C14B4 (Reaction force pressure sensor intermittent/erratic)

C14B5 (Reaction force pressure sensor invalid data)

C14C0 (Servo pressure sensor voltage circuit check)

C14C1 (Servo pressure sensor lost communication)

C14C2 (Servo pressure sensor internal malfunction)

C14C4 (Servo pressure sensor intermittent/erratic)

C14C5 (Servo pressure sensor invalid data)

P057C, P05DD (Brake pedal stroke sensor assembly open circuit)

P057D, P05DE (Brake pedal stroke sensor assembly circuit high)

P057E, P05DF (Brake pedal stroke sensor assembly intermittent/erratic)

P05E0 (Brake pedal stroke sensor assembly "1"/"2" correlation)

All of the following conditions are met

-

Servo pressure sensor circuit fail

Not detected

Brake pedal stroke sensor assembly circuit fail

Not detected

Reaction force pressure sensor circuit fail

Not detected

Brake

Off

TYPICAL MALFUNCTION THRESHOLDS

Servo pressure sensor

Less than -0.63 MPa (-6.4 kgf/cm2, -91.4 psi), or higher than 1.53 MPa (15.6 kgf/cm2, 222 psi)

COMPONENT OPERATING RANGE

All of the following conditions are met

-

Servo pressure sensor circuit fail

Not detected

Brake pedal stroke sensor assembly circuit fail

Not detected

Reaction force pressure sensor circuit fail

Not detected

Brake

Off

Servo pressure sensor

-0.63 MPa (-6.4 kgf/cm2, -91.4 psi) or more, and 1.53 MPa (15.6 kgf/cm2, 222 psi) or less

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the power switch on (IG).
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the power switch off.
  6. Turn the power switch on (IG).
  7. Turn the Techstream on.
  8. Wait 3 seconds.
  9. Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.
  10. Read the DTCs.

    HINT:

    • If a DTC is output, the system is malfunctioning.
    • If a DTC is not output, perform the following procedure.
  11. If the DTCs are not output, perform a universal trip and check for permanent DTCs.

    Click here

    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTCs are output, the system is normal.

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

Click here

PROCEDURE

1.

READ VALUE USING TECHSTREAM (SERVO PRESSURE)

(a) Select the Data List on the Techstream.

Click here

Chassis > ABS/VSC/TRAC > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Servo Pressure

Pressure value of servo

Min.: 0.00 MPa, Max.: 24.48 MPa

Brake pedal released: 0.00 to 2.10 MPa

Brake pedal is being depressed: Changes in proportion to the depression force of the brake pedal

Chassis > ABS/VSC/TRAC > Data List

Tester Display

Servo Pressure

(b) Check that the servo pressure sensor output value is within 0.00 to 1.53 MPa when the brake pedal not depressed.

OK:

The servo pressure sensor output value is within 0.00 to 1.53 MPa.

HINT:

If the servo pressure sensor output value is within 0.00 to 1.53 MPa, the skid control ECU (brake booster with master cylinder assembly) automatically performs zero point calibration every time the power switch is turned on (IG).

Therefore, if the servo pressure sensor output value is not within 0.00 to 1.53 MPa, replace the skid control ECU (brake booster with master cylinder assembly) with a new one.

NG

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

OK

2.

RECONFIRM DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

(b) Turn the power switch off.

(c) Turn the power switch on (IG).

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

HINT:

Even if the DTC is cleared, it will immediately be output again if the servo pressure sensor zero point malfunction remains.

Result

Proceed to

DTC C14C3 is not output.

A

DTC C14C3 is output.

B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

    Reaction Force Pressure Sensor Zero Point Malfunction (C14B3)

    Accumulator Pressure Sensor Stuck (C14D5)

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