Toyota Avalon Service & Repair Manual: Accumulator Pressure Sensor Stuck (C14D5)

DESCRIPTION

The accumulator pressure sensor is built into the brake booster with master cylinder assembly and detects the accumulator pressure.

If the skid control ECU (brake booster with master cylinder assembly) detects that the accumulator pressure sensor value is below the threshold, operation of the motor relay is requested and the pump motor built into the brake booster pump assembly operates.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

MIL

Note

C14D5

Accumulator Pressure Sensor Stuck

334

When the pump motor is operating, the accumulator pressure sensor signal does not change for 14 seconds or more.

Skid control ECU (brake booster with master cylinder assembly)

Comes on

  • INF Code 334: SAE Code C14D5
  • Electronically controlled brake system DTC

MONITOR DESCRIPTION

When the volume of brake fluid within the accumulator is below a certain amount, the skid control ECU (brake booster with master cylinder assembly) operates the pump motor. When the pump motor is being operated and the output value of the accumulator pressure sensor does not change substantially for a certain period of time, the skid control ECU (brake booster with master cylinder assembly) judges that the accumulator pressure sensor has a stuck malfunction and illuminates the MIL and stores this DTC.

MONITOR STRATEGY

Related DTCs

C14D5: Accumulator pressure sensor stuck

Required Sensors/Components(Main)

Brake actuator (brake booster with master cylinder assembly)

Brake booster pump assembly

Required Sensors/Components(Related)

Skid control ECU (brake booster with master cylinder assembly)

Brake actuator (brake booster with master cylinder assembly)

Brake booster pump assembly

Frequency of Operation

Continuous

Duration

7 to 14 seconds (Time depends on battery voltage)

MIL Operation

Immediately

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

C121D (Pump motor open circuit)

C14C0 (Servo pressure sensor voltage circuit check)

C14C1 (Servo pressure sensor lost communication)

C14C2 (Servo pressure sensor internal malfunction)

C14C3 (Servo pressure sensor exceeded learning limit)

C14C4 (Servo pressure sensor intermittent/erratic)

C14C5 (Servo pressure sensor invalid data)

C14D0 (Accumulator pressure sensor voltage circuit check)

C14D1 (Accumulator pressure sensor lost communication)

C14D2 (Accumulator pressure sensor internal malfunction)

C14D3 (Accumulator pressure sensor intermittent/erratic)

C14D4 (Case 1) (Accumulator pressure sensor invalid data)

C14D4 (Case 2) (Accumulator pressure sensor intermittent)

All of the following conditions are met

-

Accumulator pressure sensor fail

Not detected

Pump motor control circuit fail

Not detected

ABS/TRAC/VSC

Off

Accumulator pressure

17.1 MPa (174.4 kgf/cm2, 2480 psi) or more

Pump motor voltage (MTT)

Less than 6 V

Hydraulic used by brake booster

20 cm3 (1.2 cu.in.) or more

Change of accumulator pressure

Less than 0.12 MPa (1.2 kgf/cm2, 17 psi)

TYPICAL MALFUNCTION THRESHOLDS

Change of accumulator pressure while pump motor is intrusively operated

Less than 0.12 MPa (1.2 kgf/cm2, 17 psi)

COMPONENT OPERATING RANGE

All of the following conditions are met

-

Accumulator pressure sensor fail

Not detected

Accumulator pressure

Less than 20.85 MPa (212.6 kgf/cm2, 3024 psi)

Change of accumulator pressure

0.12 MPa (1.2 kgf/cm2, 17 psi) or more

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. Repeat the following step 3 times.
    • Fully depress the brake pedal for 2 seconds, release it and wait 1 second.
  9. Wait 14 seconds.
  10. Enter the following menus: Chassis / ABS/VSC/TRAC / Trouble Codes.
  11. Read the DTCs.

    HINT:

    • If a DTC is output, the system is malfunctioning.
    • If a DTC is not output, perform the following procedure.
  12. 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.

CHECK 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) Depress the brake pedal 10 times or more to operate the pump motor.

(e) After the pump motor stops, check for DTCs.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

DTC C14D5 is not output.

A

DTC C14D5 is output.

B

A

USE SIMULATION METHOD TO CHECK

B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

    Servo Pressure Sensor Zero Point Malfunction (C14C3)

    Open in Master Reservoir Level Switch Circuit (C120F)

    See More:

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