Brake Warning Indicator Malfunction

Brake Warning Indicator Malfunction

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.

* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Diagnostic Fault Information






Circuit/System Description

The instrument panel cluster (IPC) sees the brake fluid level switch input grounded and illuminates the Red Brake Warning indicator.

Reference Information

Schematic Reference

Hydraulic Brake Schematics Electrical Diagrams

Connector End View Reference

Component Connector End Views 1-2 Shift Solenoid (SS) Valve (MN5)

Description and Operation

Brake Warning System Description and Operation Brake Warning System

Electrical Information Reference

* Circuit Testing Circuit Testing

* Connector Repairs Connector Repairs

* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections

* Wiring Repairs Wiring Repairs

Scan Tool Reference

Control Module References Programming and Relearning for scan tool information

Circuit/System Verification

1. Inspect for proper brake fluid level, the fluid level should be at or above the proper level.

• If low, refer to Brake Fluid Loss Brake Fluid Loss.

2. Command the IPC display test with a scan tool, the warning indicator should turn ON.

• If the red brake warning indicator does not illuminate, replace the IPC.

3. Observe the scan tool EBCM Brake Fluid Level Sensor parameter. The reading should be OK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.

2. Test for less than 5 ohm between the ground circuit terminal A and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify the scan tool EBCM Brake Fluid Level Sensor parameter is OK.

• If not the specified value, test the signal circuit terminal B for a short to ground. If the circuit tests normal, replace the IPC.

4. Install a 3A fused jumper wire between the signal circuit terminal B and ground. Verify the scan tool EBCM Brake Fluid Level Sensor parameter is Low.

• If not the specified value, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the IPC.

5. If all circuits test normal, test or replace the brake fluid level switch.

Component Testing

1. Ignition OFF, disconnect the harness connector at the brake fluid level switch.

2. Test for infinite resistance between the ground terminal A and the signal terminal B.

• If less than the specified value, replace the brake fluid level switch.

Repair Instructions

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

* Brake Fluid Level Indicator Switch Replacement Service and Repair

* Control Module References Programming and Relearning for IPC replacement, setup, and programming