Schematic Reference: Brake Warning System Schematics

1

Did you review the Brake Warning System Description and Operation and the Brake Assist System Description and Operation and perform the necessary inspections?

Go to Step 2

Go to Symptoms - Hydraulic Brakes

Perform the Brake Assist System Diagnosis

Did you find and correct the condition?

Go to Step 8

Go to Step 3

1. Disconnect the supplemental brake assist connector.
2. Turn the ignition to the run position.
3. Use a DMM in order to test for voltage on the supplement brake assist signal circuit

Is there voltage on the supplemental brake assist signal circuit?

Go to Step 5

Go to Step 4

1. Disconnect the instrument panel cluster connector.
2. Test the supplemental brake assist signal circuit for an open or a short to ground.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 8

Go to Step 6

1. Connect the supplemental brake assist connector.
2. Disconnect the instrument panel cluster connector.
3. Connect a DMM from battery possitive voltage to the Supplemental brake assist signal circuit
4. Turn the ignition to the RUN position while watching the DMM.

Does the DMM flash battery voltage?

Go to Step 6

Go to Step 7

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

Did you complete the replacement?

Go to Step 8

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Replace the Supplemental Brake Assist pump motor assembly. Refer to Power Brake Booster Auxiliary Pump Replacement .

Did you complete the replacement?

Go to Step 8

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Start the engine.

Does the REDUCED BRAKE POWER message stay on?

Go to Step 2

System OK