Diesel Data: Automotive Repair
Home >> Chevrolet >> 2008 >> Corvette V8-7.0L >> Repair and Diagnosis >> Brakes and Traction Control >> Hydraulic System >> Testing and Inspection >> Symptom Related Diagnostic Procedures >> Brake Warning Indicator Malfunction

Brake Warning Indicator Malfunction



Brake Warning Indicator Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



Circuit/System Description

The instrument panel cluster (IPC) monitors the brake fluid level switch circuit, the park brake switch circuit, and the serial data bus. If either switch circuit is grounded, or if the IPC receives a serial data indicator request, the IPC illuminates the brake warning indicator.


Reference Information
Schematic Reference

Hydraulic Brake Schematics ([1][2]Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for Scan Tool Information


Circuit/System Verification

1. Start the engine. Verify that the brake warning indicator illuminates during the IPC bulb check.

• If the brake warning indicator does not illuminate during the bulb check, replace the IPC.

2. Observe the driver information center (DIC). Verify that the CHECK BRAKE FLUID message is not displayed.

• If the CHECK BRAKE FLUID message is displayed, then refer to Circuit/System Testing: CHECK BRAKE FLUID Message and Brake Warning Indicator Always On.

3. Apply the parking brake. Verify that the brake warning indicator illuminates.

• If the brake warning indicator does not illuminate, then refer to Circuit/System Testing: Brake Warning Indicator Inoperative when Park Brake is Applied.

4. Release the parking brake. Verify that the brake warning indicator turns off.

• If the brake warning indicator does not turn off, then refer to Circuit/System Testing: Brake Warning Indicator Always On.

5. Remove all of the brake fluid from the master cylinder reservoir. Verify that the brake warning indicator illuminates on the IPC.

• If the brake warning indicator does not illuminate, then refer to Circuit/System Testing: Brake Warning Indicator Inoperative when Brake Fluid is Low.




Circuit/System Testing
Brake Warning Indicator Inoperative when Park Brake is Applied

1. Ignition ON. With the scan tool, select Instrument Panel Cluster, Special Functions, Display Test. Command the instrument panel lamps ON. Verify that the brake warning indicator turns ON.

• If the brake warning indicator does not turn ON, replace the IPC.

2. Disconnect the park brake switch. Connect a 3 amp fused jumper wire between the signal circuit terminal A of the park brake switch and ground. Ignition ON, Verify that the brake warning indicator is OFF.

• If the brake warning indicator turns ON, replace the park brake switch.

3. Test the signal circuit for continuity. Verify that the signal circuit does not have a high resistance or an open.

• If a high resistance or an open is found, repair the circuit.

4. Replace the IPC.


Brake Warning Indicator Inoperative when Brake Fluid is Low

1. Ignition ON. With the scan tool, select Instrument Panel Cluster, Special Functions, Display Test. Command the instrument panel lamps ON. Verify that the brake warning indicator turns ON.

• If the brake warning indicator does not turn ON, replace the IPC.

2. Disconnect the brake fluid level switch. Connect a 3 amp fused jumper wire between the signal circuit terminal A and the ground circuit terminal B of the brake fluid level switch . Ignition ON, Verify that the brake warning indicator is OFF.

• If the brake warning indicator turns ON, replace the brake fluid level switch.

3. Test the signal circuit and the ground circuit for continuity. Verify that the signal circuit and the ground circuit does not have a high resistance or an open.

• If a high resistance or an open is found, repair the circuit.

4. Replace the IPC.


Brake Warning Indicator Always On

1. Engine running. Observe the driver information center (DIC). Verify that the CHECK BRAKE FLUID message is not displayed on the DIC.

• If the CHECK BRAKE FLUID message is displayed on the DIC, go to Circuit/System Testing: CHECK BRAKE FLUID Message and Brake Warning Indicator Always On.

2. Ignition ON. With the scan tool, select Instrument Panel Cluster, Special Functions, Display Test. Command the instrument panel lamps OFF. Verify that the brake warning indicator turns OFF.

• If the brake warning indicator does not turn OFF, replace the IPC.

3. Disconnect the park brake switch connector. With a scan tool, observe the Park Brake Switch parameter. Verify that the scan tool Park Brake Switch parameter is reading Applied.

• If the scan tool Park Brake Switch parameter is Released, replace the park brake switch.

4. Test the park brake switch signal circuit for a short to ground. Verify that the park brake switch signal circuit is not shorted to ground.

• If the park brake switch signal circuit is shorted to ground, repair the circuit.

5. Replace the IPC.


CHECK BRAKE FLUID Message and Brake Warning Indicator Always On

1. Inspect the master cylinder reservoir for the proper brake fluid level.

• If brake fluid level is low, refer to Hydraulic Brake System Diagnosis (Component Tests and General Diagnostics) .

2. Ignition ON. With the scan tool, select Instrument Panel Cluster, Special Functions, Display Test. Command the instrument panel lamps OFF. Verify that the brake warning indicator turns OFF.

• If the brake warning indicator does not turn OFF, replace the IPC.

3. Disconnect the brake fluid level switch connector. With a scan tool, observe the Brake Fluid Level Switch parameter. Verify that the scan tool Brake Fluid Level Switch parameter is On.

• If the scan tool Brake Fluid Level Switch parameter is Off, replace the brake fluid level switch.

4. Test the brake fluid level sensor signal circuit for a short to ground. Verify that the brake fluid level sensor signal circuit is not shorted to ground.

• If the brake fluid level sensor signal circuit is shorted to ground, repair the circuit.

5. Replace the IPC.



Component Testing
Park Brake Switch

1. Ignition OFF. Release the park brake. Disconnect the park brake switch connector. Verify that continuity does not exist between terminal A of the park brake switch and ground.

• If there is continuity between terminal A of the park brake switch and ground when the park brake is released, replace the parking brake indicator switch.

2. Apply the park brake. Verify that continuity exists between terminal A of the park brake switch and ground.

• If there is no continuity between terminal A of the park brake switch and ground when the park brake is applied, replace the parking brake indicator switch.


Brake Fluid Level Switch

1. Inspect the master cylinder reservoir for the proper brake fluid level.

• If brake fluid level is low, refer to Hydraulic Brake System Diagnosis (Component Tests and General Diagnostics) .

2. Ignition OFF. Disconnect the brake fluid level switch connector. Verify that continuity does not exist between terminal A and terminal B of the brake fluid level switch.

• If there is continuity between terminal A and terminal B of the brake fluid level switch when the master cylinder reservoir is full, replace the brake fluid level indicator switch.

3. Remove all of the brake fluid from the master cylinder reservoir. Verify that continuity exists between terminal A and terminal B of the brake fluid level switch.

• If there is no continuity between terminal A and terminal B of the brake fluid level switch when the master cylinder reservoir is empty, replace the brake fluid level indicator switch.




Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Brake Fluid Level Indicator Switch Replacement (Service and Repair)
* Parking Brake Indicator Switch Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for IPC replacement, setup, and programming


Diesel-Data.com