Schematic Reference: Brake Warning System Schematics

1

Did you perform the Hydraulic Brake Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Hydraulic Brakes

1. Turn OFF the ignition.
2. Turn ON the ignition, with the engine OFF.
3. Observe the red Brake indicator.

Does the red Brake indicator illuminate briefly during the displays test?

Go to Step 3

Go to Step 14

Apply the park brake.

Does the red Brake indicator illuminate?

Go to Step 4

Go to Step 5

1. Turn OFF the ignition.
2. Release the park brake.
3. Disconnect the brake fluid level switch.
4. Connect a 3 amp fused jumper wire between the signal circuit of the brake fluid level switch and the ground circuit of the brake fluid level switch.
5. Turn ON the ignition, with the engine OFF.

Does the red Brake indicator illuminate?

Go to Step 13

Go to Step 9

1. Turn OFF the ignition.
2. Disconnect the park brake switch.
3. Connect a 3 amp fused jumper wire between the signal circuit of the park brake switch and a good ground.
4. Turn ON the ignition, with the engine OFF.

Does the red Brake indicator illuminate?

Go to Step 12

Go to Step 6

1. Turn OFF the ignition.
2. Leave the fused jumper connected.
3. Disconnect the automatic headlamp control module.
4. Connect a 3 amp fused jumper wire between the park brake switch signal circuit (CKT 233) of the automatic headlamp control module and the park brake switch signal circuit (CKT 1830) of the automatic headlamp control module
5. Turn ON the ignition, with the engine OFF.

Does the red Brake indicator illuminate?

Go to Step 11

Go to Step 7

Test the signal circuit of the park brake switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 8

Test the park brake switch signal circuit between the body control module and the automatic headlamp control module for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 15

Test the signal circuit of the brake fluid level switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 10

Test the ground circuit of the brake fluid level switch for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 14

Inspect for poor connections at the harness connector of the automatic headlamp control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 16

Inspect for poor case ground or poor connections at the harness connector of the park brake switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 17

Inspect for poor connections at the harness connector of the brake fluid level switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 18

Inspect for poor connections at the harness connector of the IPC. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 19

Inspect for poor connections at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 21

Go to Step 20

Replace the automatic headlamp control module. Refer to Headlamp Control Module Replacement in Lighting Systems.

Did you complete the repair?

Go to Step 21

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

Did you complete the repair?

Go to Step 21

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Replace the brake fluid level switch. Refer to Brake Fluid Level Indicator Switch Replacement .

Did you complete the repair?

Go to Step 21

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Replace the instrument panel cluster (IPC). Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.

Did you complete the repair?

Go to Step 21

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Replace the body control module. Refer to Body Control Module Replacement in body control system.

Did you complete the repair?

Go to Step 21

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Operate the vehicle in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2