Toyota Avalon (XX50): Brake Control Warning Light does not Come ON. Brake Control Warning Light Remains ON. Brake Hold Operated Indicator Light Circuit

Brake Control Warning Light does not Come ON

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.

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

(a) Check if CAN communication system DTCs are output.

Click here

B

INSPECT CAN COMMUNICATION SYSTEM

A

(a) Select the Active Test on the Techstream.

Click here

(b) Check the operating condition of the brake warning light / yellow (minor malfunction) when operating it using the Techstream.

A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

(a) Perform the Active Test of the combination meter assembly (meter CPU) using the Techstream.

Click here

(b) Check the combination meter assembly.

OK:

The brake warning light / yellow (minor malfunction) turns on or off in accordance with Techstream operation.

OK

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

NG

INSPECT METER / GAUGE SYSTEM

Brake Control Warning Light Remains ON

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) is connected to the combination meter assembly via CAN communication.

If the skid control ECU (brake booster with master cylinder assembly) stores a DTC, the brake warning light / yellow (minor malfunction) comes on in the combination meter assembly.

WIRING DIAGRAM

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

(a) Check if CAN communication system DTCs are output.

Click here

B

INSPECT CAN COMMUNICATION SYSTEM

A

(a) Check if the skid control ECU (brake booster with master cylinder assembly) connector is securely connected.

OK:

The connector is securely connected.

NG

CONNECT CONNECTOR TO BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY CORRECTLY

OK

(a) Check the auxiliary battery voltage.

Standard Voltage:

NG

CHARGE OR REPLACE AUXILIARY BATTERY

OK

(a) Select the Data List on the Techstream.

Click here

(b) Check the Techstream display condition of the brake warning light / yellow (minor malfunction).

A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

INSPECT METER / GAUGE SYSTEM

Brake Hold Operated Indicator Light Circuit

DESCRIPTION

The brake hold operated indicator light illuminates when the brake hold system is operating (vehicle stopped via brake fluid pressure hold) and turns off when the brake hold system operation is finished (brake fluid pressure decreases).

The brake hold system may not operate depending on vehicle conditions even when the system is in standby mode and the brake hold standby indicator light is illuminated.

If there is a system malfunction that causes brake hold control to be prohibited, when the vehicle is under the following conditions and the brake hold switch (electric parking brake switch assembly) is turned on, the brake hold operated indicator light blinks.

• Vehicle Conditions:
  1. The driver side door is closed.
  2. The driver side seat belt is fastened.

HINT:

• When the power switch is turned off during brake hold operation, control stops.
• If brake hold control does not operate even when the vehicle stops, depress on the brake pedal again firmly to stop the vehicle.

  If brake hold control still does not operate, confirm the conditions for brake hold control to operate.

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

(a) Check that the brake hold standby indicator light operates normally.

Click here

(b) If the brake hold operated indicator light does not illuminate although the brake hold standby indicator light is illuminated, check that the following brake hold operation (maintaining brake fluid pressure) conditions are met.

1. System is in operation standby state (brake hold standby indicator light is illuminated).
2. Shift position is not P or R.
3. Driver is depressing brake pedal and vehicle is fully stopped.
4. Driver is not depressing accelerator pedal.
5. Vehicle is not on steep decline.

HINT:

If a malfunction occurs in one of the following systems, the brake hold operated indicator light will blink. If this occurs, perform troubleshooting on the malfunctioning system.

• Brake system
• Electric parking brake system
• Hybrid control system

NEXT

(a) Turn the power switch off.

(b) Perform the Active Test of the combination meter assembly (meter CPU) using the Techstream.

Click here

(c) Check the combination meter assembly.

OK:

The brake hold operated indicator light turns on or off in accordance with Techstream operation.

NG

INSPECT METER / GAUGE SYSTEM

OK

(a) Select the Active Test on the Techstream.

Click here

(b) Check the operating condition of the brake hold operated indicator light when operating it using the Techstream.

A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

USE SIMULATION METHOD TO CHECK