Last Modified: 01-30-2024 6.11:8.1.0 Doc ID: RM100000002GAKW
Model Year Start: 2024 Model: RAV4 Prod Date Range: [10/2023 -           ]
Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/o Vacuum Brake Booster): C125609; Accumulator Low Pressure Abnormality Component Failure; 2024 MY RAV4 RAV4 HV [10/2023 -        ]

DTC

C125609

Accumulator Low Pressure Abnormality Component Failure

DESCRIPTION

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

The No. 1 skid control ECU (brake booster with master cylinder assembly) turns on the brake system warning light (red indicator) and brake system warning light (yellow indicator), and sounds the meter buzzer if it senses a decrease in the accumulator pressure.

DTC C125609 may be stored if the accumulator pressure drops due to frequent braking (this is not a malfunction).

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Note

C125609

Accumulator Low Pressure Abnormality Component Failure

When the vehicle speed is 3 km/h (2 mph) or more, the accumulator pressure is excessively low.

(DTCs will be stored and the buzzer will sound when the above condition is met.)
  • Accumulator pressure dropped due to frequent brake pedal operation (not a malfunction)
  • Pump motor malfunction
  • Accumulator deterioration
  • Accumulator pressure sensor (brake booster with master cylinder assembly)
  • Supply voltage reduced

Comes on
  • SAE Code: C1256
  • Output ECU: No. 2 skid control ECU (brake actuator assembly)

MONITOR DESCRIPTION

The No. 2 skid control ECU (brake actuator assembly) monitors the value of the accumulator pressure using the accumulator pressure sensor.

If any of the following conditions are met for a certain amount of time, the No. 2 skid control ECU (brake actuator assembly) judges that the accumulator pressure is low and illuminates the MIL and stores this DTC.

  • The accumulator pressure does not increase when the pump motor is operated.
  • The accumulator pressure is not a specific value or more after starting the No. 2 skid control ECU (brake actuator assembly).
  • The accumulator pressure is less than a specific value.

MONITOR STRATEGY

Related DTCs

C1256: Brake booster motor pressure too low

Required Sensors/Components(Main)

Brake booster with accumulator pump assembly

Brake actuator (brake booster with master cylinder assembly)

Required Sensors/Components(Related)

No. 2 skid control ECU (brake actuator assembly)

Brake actuator (brake booster with master cylinder assembly)

Stop light switch assembly

Frequency of Operation

Continuous

Duration

1.698 to 9 seconds (Time depends on auxiliary battery voltage): C1256 (Case 1-1)

3 seconds: C1256 (Case 1-2)

33 to 99 seconds (Time depends on auxiliary battery voltage): C1256 (Case 1-3)

MIL Operation

Immediately

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

All

Monitor runs whenever the following DTCs are not stored

C0573 (Case 1): Accumulator pressure sensor lost communication

C0573 (Case 2): Accumulator pressure sensor internal malfunction

C0573 (Case 3): Accumulator pressure sensor invalid data

C149E: Accumulator pressure sensor voltage circuit low

C149F: Accumulator pressure sensor voltage circuit high

C14D3: Accumulator pressure sensor intermittent/erratic

Case 1-1

All of the following conditions are met

-

Brake booster pressure sensor fail

Not detected

Brake booster pressure

Less than 16.2 Mpa (165.2 kgf/cm2, 2349 psi)

Brake

Off

Brake system voltage 1 (VM1)

Higher than 7.3 V

Servo pressure sensor fail

Not detected

Case 1-2

All of the following conditions are met

-

Brake booster pressure sensor fail

Not detected

Brake booster pressure

Less than 16.2 Mpa (165.2 kgf/cm2, 2349 psi)

Brake booster motor control circuit high

Not detected

Brake

Off

Brake system voltage 1 (VM1)

Higher than 7.3 V

Servo pressure sensor fail

Not detected

Case 1-3

Both of the following conditions are met

-

Brake booster pressure sensor fail

Not detected

Brake booster pressure

Less than 16.2 Mpa (165.2 kgf/cm2, 2349 psi)

TYPICAL MALFUNCTION THRESHOLDS

Case 1-1

Brake booster pressure increase when brake booster motor is operating

Less than 0.25 MPa (2.5 kgf/cm2, 36 psi)

Case 1-2

Brake booster pressure after ECU power on

Less than 6 MPa (61.2 kgf/cm2, 870 psi)

Case 1-3

Brake booster pressure

Less than 14 MPa (142.8 kgf/cm2, 2031 psi)

COMPONENT OPERATING RANGE

All

Both of the following conditions are met

-

Brake booster pressure sensor fail

Not detected

Brake booster pressure

15 MPa (153.0 kgf/cm2, 2175 psi) or more

CONFIRMATION DRIVING PATTERN

NOTICE:

When performing the normal judgment procedure, make sure that the driver door is closed and is not opened at any time during the procedure.

HINT:

  • After repair has been completed, clear the DTC and then check that the vehicle has returned to normal by performing the following All Readiness check procedure.
  • When clearing the permanent DTCs, refer to the "CLEAR PERMANENT DTC" procedure.
  1. Connect the GTS to the DLC3.
  2. Turn the ignition switch to ON and turn the GTS on.
  3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  4. Turn the ignition switch off.
  5. Turn the ignition switch to ON (READY) and turn the GTS on.
  6. Repeat the following step 10 times. [*1]
    • Fully depress the brake pedal for 2 seconds, release it and wait 1 second.
  7. Wait 100 seconds. [*2]

    HINT:

    [*1] to [*2]: Normal judgment procedure.

    The normal judgment procedure is used to complete DTC judgment and also used when clearing permanent DTCs.

  8. Enter the following menus: Chassis / Brake/EPB / Utility / All Readiness.
  9. Check the DTC judgment result.

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
    • If the judgment result shows INCOMPLETE, perform driving pattern again.

WIRING DIAGRAM

Refer to DTC C059400.

Click here 2024 MY RAV4 RAV4 HV [10/2023 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/o Vacuum Brake Booster): C059400; Brake Booster Motor "A" Performance

CAUTION / NOTICE / HINT

NOTICE:

  • Inspect the fuses for circuits related to this system before performing the following procedure.
  • After replacing the No. 1 skid control ECU (brake booster with master cylinder assembly), perform "Calibration" after performing "Reset Memory".

    Click here 2022 - 2024 MY RAV4 RAV4 HV [12/2021 -        ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM (w/o Vacuum Brake Booster): UTILITY

PROCEDURE

1.

CHECK DTC

(a) Check the DTCs that are output.

Chassis > Brake Booster > Trouble Codes

Chassis > Brake/EPB > Trouble Codes

Result

Proceed to

Only DTC C125609 is output.

A

DTCs other than C125609 are output.

B
B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS
A

2.

INSPECT BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY

(a) Turn the ignition switch off.

*a

Component without harness connected

(Brake Booster with Accumulator Pump Assembly)

(b) Make sure that there is no looseness at the locking part and the connecting part of the connector.

OK:

The connector is securely connected.

(c) Disconnect the A106 brake booster with accumulator pump assembly connector.

(d) Check both the connector case and the terminals for deformation and corrosion.

OK:

No deformation or corrosion.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

1 (BM1) - 2 (GND1)

Always

10 Ω or less
NG

REPLACE BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY

OK

3.

READ VALUE USING GTS (ACCUMULATOR PRESSURE)

(a) Reconnect the A106 brake booster with accumulator pump assembly connector.

(b) Disconnect the A103*1 or A110*2 brake pedal stroke sensor assembly connector.

  • *1: except TMC Made
  • *2: for TMC Made

(c) Depress the brake pedal several times to operate the pump motor, then wait until it stops.

(d) After the pump motor stops, wait for 30 seconds, then check the drop in the accumulator pressure sensor output value and the state of the pump motor.

Chassis > Brake Booster > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

ECB Motor Relay

Motor relay operation request

OFF / ON

OFF: Relay off

ON: Relay on

ECB: Electronically Controlled Brake System

Accumulator Pressure

Accumulator pressure output value

Min.: 0.00 MPa

Max.: 24.48 MPa

15.00 to 21.00 MPa (Pressure stable and pump motor stopped)

When brake fluid is stored in the accumulator: Accumulator pressure changes in accordance with volume of fluid stored in the accumulator

Chassis > Brake Booster > Data List

Tester Display

ECB Motor Relay

Accumulator Pressure

Result

Proceed to

The drop in the accumulator pressure sensor output value is less than 2.50 MPa 30 seconds after the pump motor stops, and the pump motor does not operate within 30 seconds after the pump motor stops.

A

The drop in the accumulator pressure sensor output value is 2.50 MPa or more 30 seconds after the pump motor stops, or the pump motor operates within 30 seconds after the pump motor stops.

B
A

USE SIMULATION METHOD TO CHECK

B

4.

READ VALUE USING GTS (SERVO PRESSURE)

(a) Turn the ignition switch off.

(b) Reconnect the A103*1 or A110*2 brake pedal stroke sensor assembly connector.

  • *1: except TMC Made
  • *2: for TMC Made

(c) Perform the Active Test and operate the linear solenoid (SLR) in the brake booster with master cylinder assembly.

(d) Check that the servo pressure output value does not increase when performing the Active Test.

Chassis > Brake Booster > Active Test

Tester Display

Measurement Item

Control Range

Restrict Condition

Diagnostic Note

ECB Solenoid (SLR)

Linear solenoid reduction valve (SLR)

Solenoid Start (Activate)

Solenoid SLR

(It is possible to set the current)

Vehicle condition:

  • Vehicle stopped
  • Shift lever is in P
  • Apply the parking brake

ECB: Electronically Controlled Brake System

Chassis > Brake Booster > 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 1.53 MPa

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

Chassis > Brake Booster > Active Test

Active Test Display

ECB Solenoid (SLR)

Data List Display

Servo Pressure

OK:

The servo pressure output value does not increase when performing the Active Test.

HINT:

  • If the servo pressure output value increases, an internal brake fluid leak in the brake booster with master cylinder assembly is suspected.
  • Perform the Active Test with the current set to maximum.

Result

Proceed to

The servo pressure output value increases.

A

The servo pressure output value does not increase.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY AND BRAKE BOOSTER WITH ACCUMULATOR PUMP ASSEMBLY

for Brake Booster with Master Cylinder Assembly: Click here 2024 MY RAV4 RAV4 HV [10/2023 -        ]; BRAKE SYSTEM (OTHER): BRAKE BOOSTER (w/o Vacuum Brake Booster): REMOVAL

for Brake Booster with Accumulator Pump Assembly: Click here 2024 MY RAV4 RAV4 HV [10/2023 -        ]; BRAKE SYSTEM (OTHER): BRAKE BOOSTER PUMP (w/o Vacuum Brake Booster): REMOVAL