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 cluster turns ON the brake warning indicator for 5 s after ignition ON. When the electronic brake control module detects a fault, it sends a serial data message to the instrument cluster commanding the brake warning indicator ON.
Reference Information
Schematic Reference
Hydraulic Brake Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
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. Verify that the brake fluid has the proper level. The fluid level should be above minimum level.
• If low
Refer to Brake Fluid Loss Brake Fluid Loss.
• If above minimum level
2. Ignition ON.
3. Verify the scan tool Electronic Brake Control Module, Brake Fluid Level Sensor parameter is Ok.
• If the parameter is Low
Refer to Circuit/System Testing.
• If the parameter is Ok
4. Verify the brake warning indicator turns ON and OFF, when commanding the instrument cluster All Indicators ON and OFF with a scan tool.
• If the brake warning indicator does not turn ON and OFF
Replace the P16 Instrument Cluster.
• If the brake warning indicator turns ON and OFF
5. All OK.
Circuit/System Testing
Note: Circuit/System Verification must be performed before Circuit/System Testing.
1. Ignition OFF, disconnect the harness connector at the B20 Brake Fluid Level Switch.
2. Test for less than 10 ohms between the ground circuit terminal 2 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify the scan tool Electronic Brake Control Module, Brake Fluid Level Sensor parameter is Low.
• If the parameter is not Low
1. Ignition OFF, disconnect the harness connector at the K17 Electronic Brake Control Module.
2. Test for infinite resistance between the signal circuit terminal 1 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K17 Electronic Brake Control Module.
• If the parameter is Low
5. Install a 3 A fused jumper wire between the signal circuit terminal 1 and ground.
6. Verify the scan tool Electronic Brake Control Module, Brake Fluid Level Sensor parameter is Ok.
• If the parameter is Low
1. Ignition OFF, disconnect the harness connector at the K17 Electronic Brake Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V.
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K17 Electronic Brake Control Module.
• If the parameter is Ok
7. Test or replace the B20 Brake Fluid Level Switch.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Brake Fluid Level Indicator Switch Replacement Service and Repair
* Control Module References Programming and Relearning for Control Module replacement, programming and setup.