Vehicle Stability Control System Brake Warning Light Remains On

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

CHECK FOR DTC

CHECK IF SKID CONTROL ECU CONNECTOR IS SECURELY CONNECTED

CHECK TERMINAL VOLTAGE (IG1 TERMINAL)

CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)

CHECK BRAKE BOOSTER ASSEMBLY

INSPECT BRAKE FLUID LEVEL WARNING SWITCH

CHECK VACUUM WARNING SWITCH ASSEMBLY

INSPECT PARKING BRAKE SWITCH ASSEMBLY

CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - COMBINATION METER AND PARKING BRAKE SWITCH)

CHECK HARNESS AND CONNECTOR (COMBINATION METER - BODY GROUND)

PERFORM ACTIVE TEST USING INTELLIGENT TESTER (BRAKE WARNING LIGHT)

DESCRIPTION

1. The skid control ECU (brake actuator assembly) connector is disconnected from the skid control ECU (brake actuator assembly).
   
2. The brake fluid level is insufficient.
   
3. The parking brake is applied.
   
4. The vacuum inside the brake booster decreases.
   
5. There is an open circuit in the harness between the combination meter and the skid control ECU (brake actuator assembly).
   
6. EBD operation has been disabled.
   

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

1. After replacing the brake actuator assembly, perform calibration (HILUX_TGN26 RM000000XHR073X.html).
   
2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
   
3. Before disconnecting the connector, make sure that there are no problems with the connection.
   
4. After disconnecting the connector, make sure that the connector case and terminals are not deformed or corroded.
   

1. Check for DTCs (HILUX_TGN26 RM000000XHV0CGX.html).
   

   Result

   Result	Proceed to
   DTC is not output	A
   DTC is output	B

1. Check if the skid control ECU (brake actuator assembly) connector is securely connected.
   

   OK:

   The connector is securely connected.
   

1. Turn the ignition switch off.
   

2. Disconnect the skid control ECU (brake actuator assembly) connector.
   

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

   Standard Voltage:

   Tester Connection	Switch Condition	Specified Condition
   A36-34 (IG1) - Body ground	Ignition switch ON	11 to 14 V

   Text in Illustration

   *a	Front view of wire harness connector (to Skid Control ECU [Brake Actuator Assembly])

1. Turn the ignition switch off.
   

2. Disconnect the skid control ECU (brake actuator assembly) connector.
   

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   A36-1 (GND1) - Body ground	Always	Below 1 Ω

1. Check the brake booster assembly (HILUX_TGN26 RM0000010KJ00XX.html).
   

1. Turn the ignition switch to ON.
   

2. With the brake fluid at the specified level, disconnect the brake fluid level warning switch (brake master cylinder reservoir sub-assembly) connector and check the brake warning light.
   

   Result

   Result	Proceed to
   Brake warning light does not turn off	A
   Brake warning light turns off	B

   HINT:

   If the brake warning light turns off, the brake fluid level warning switch (brake master cylinder reservoir sub-assembly) has an internal short circuit.

1. Start the engine.
   

2. Idle the engine.
   

3. Disconnect the vacuum warning switch connector and check the brake warning light.
   

   Result

   Result	Proceed to
   Brake warning light does not turn off	A
   Brake warning light turns off	B

   HINT:

   If the brake warning light turns off, the vacuum warning switch has an internal short circuit.

1. Turn the ignition switch off.
   

2. Remove the parking brake switch assembly (HILUX_TGN26 RM000001C4X01LX.html).
   

3. Inspect the parking brake switch (HILUX_TGN26 RM000001C4V01MX.html).
   

1. Turn the ignition switch off.
   

2. Disconnect the skid control ECU (brake actuator assembly) connector.
   

3. Disconnect the G19 combination meter connector.
   

4. Disconnect the parking brake switch connector.
   

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   A36-8 (BRL) - G19-26 (PKBI)	Always	Below 1 Ω
   A36-8 (BRL) - Body ground	Always	10 kΩ or higher
   A36-29 (PKB) - K6-1	Always	Below 1 Ω
   A36-29 (PKB) - Body ground	Always	10 kΩ or higher

1. Turn the ignition switch off.
   

2. Disconnect the G19 combination meter connector.
   

3. Disconnect the skid control ECU (brake actuator assembly) connector.
   

4. Disconnect the brake fluid level warning switch (brake master cylinder reservoir assembly) connector.
   

5. Disconnect the vacuum warning switch connector.
   

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

   Standard Resistance:

   Tester Connection	Condition	Specified Condition
   G19-36 (SW) - Body ground	Always	10 kΩ or higher

1. Turn the ignition switch off.
   

2. Connect the intelligent tester to the DLC3.
   

3. Turn the ignition switch to ON.
   

4. Turn the intelligent tester on.
   

5. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.
   
   

   ABS/VSC/TRC

   Tester Display	Test Part	Control Range	Diagnostic Note
   Brake Warning Light	Brake warning light	Warning light ON / OFF	Observe the combination meter.

6. When performing the Brake Warning Light Active Test, check Brake Warning Light in the Data List.
   
   

   ABS/VSC/TRC

   Tester Display	Measurement Item / Range	Normal Condition	Diagnostic Note
   Brake Warning Light	Brake warning light / ON or OFF	ON: Brake warning light on OFF: Brake warning light off	-