Schematic Reference: Brake Warning System Schematics

1

Did you review the Hydraulic Brakes System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Hydraulic Brakes

Verify a fault is present.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

1. Install a scan tool.
2. Select the Instrument Panel Cluster Special Functions menu.
3. Command the Brake Lamp Off.

Does the Brake Warning indicator turn OFF?

Go to Step 4

Go to Step 12

1. Select Input 1 from the BCM Data Display menu.
2. Ensure the park brake is released.
3. Observe the Park Brake status.

Does the scan tool display released?

Go to Step 5

Go to Step 6

Disconnect the Brake Fluid Level Switch.

Does the Brake Warning indicator turn OFF?

Go to Step 13

Go to Step 9

Disconnect the park brake switch.

Does the Brake Warning indicator turn OFF?

Go to Step 10

Go to Step 7

Disconnect the ignition switch

Does the Brake Warning indicator turn OFF?

Go to Step 15

Go to Step 8

1. Disconnect from the BCM, the harness connector containing the park brake switch output circuit.
2. Test the park brake switch output circuit for a short to ground. . Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 11

Disconnect from the EBCM, the harness connector containing the brake fluid level sensor signal circuit.

Test the brake fluid level sensor signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 16

Go to Step 14

Replace the park brake switch. Refer to Parking Brake Indicator Switch Replacement in Park Brake.

Did you complete the replacement?

Go to Step 16

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Important: Perform the set up procedure for the BCM.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 16

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Replace the Instrument Panel Cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Did you complete the replacement?

Go to Step 16

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Replace the brake fluid level switch. Refer to Master Cylinder Reservoir Replacement .

Did you complete the replacement?

Go to Step 16

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Important: Use the scan tool in order to perform the Tire Size Calibration procedure.

Replace the EBCM. Refer to Electronic Brake Control Module Replacement in Antilock Brake System.

Did you complete the replacement?

Go to Step 16

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Replace the Ignition switch. Refer to Ignition Switch Replacement - On Vehicle in Steering Wheel and Column - Tilt or Ignition Switch Replacement - On Vehicle in Steering Wheel and Column - Standard.

Did you complete the replacement?

Go to Step 16

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Verify the system is repaired.

Does the system operate normally?

System OK

Go to Step 2