Was the Park Brake System Check performed?

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Go to Step 2

Go to Park Brake Diagnostic System Check

1. Turn the ignition switch to OFF.
2. Remove the PRK BRK fuse from the rear fuse block.
3. Connect a DMM set to amps scale across the terminals of the removed fuse.
4. Connect a scan tool to the data link connector (DLC) and turn the ignition switch to ON.
5. Establish communication with the rear integration module (RIM).
6. Under special functions menu, select output control.
7. Using the scan tool, command the park brake relay A (park brake release relay) on and off.

Does the current through the DMM change from high to low as the relay cycles?

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Go to Step 10

Go to Step 3

Using the scan tool, command the park brake relay B (park brake ratchet eng relay) on and off.

Does the current through the DMM change from high to low as the relay cycles?

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Go to Step 14

Go to Step 4

1. Disconnect the park brake release solenoid connector.
2. Connect a scan tool to the data link connector (DLC).
3. Turn the ignition switch to ON.
4. Establish communication with the rear integration module (RIM).
5. Under special functions menu, select output control.
6. Connect a DMM from the park brake release solenoid connector terminal A to ground.
7. Using the scan tool, command park brake relay A (park brake ratchet relay) on and off.

Does the voltage change from 0 to 12 volts on command?

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Go to Step 11

Go to Step 5

1. Remove park brake relay A from the rear fuse block.
2. Backprobe with a DMM to battery positive voltage (B+), the rear fuse block connector C2 terminal B1.
3. Using the scan tool as in step 4, command the park brake relay A on and off.

Does the voltage change from 0 to 12 volts on command?

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Go to Step 8

Go to Step 6

Check CKT 1607 (PNK) for a short to ground.

Is the circuit OK?

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Go to Step 15

Go to Step 7

Repair CKT 1607 (PNK).

Is the circuit repair complete?

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Go to Step 16

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1. Turn the ignition switch to OFF.
2. Install a known good relay in place of park brake relay A.
3. Turn the ignition switch to ON.
4. Connect a DMM from the park brake release solenoid terminal A to ground.
5. Using the scan tool as in step 4, command park brake relay A on, then off.

Is the voltage within the specified range?

10-15 V

Go to Step 10

Go to Step 9

Repair short to battery voltage on CKT 1628 (BLK).

Is the circuit repair complete?

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Go to Step 16

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1. Check park brake relay A socket for poor terminal contact.
2. If OK, park brake relay A (already replaced in step 8) is faulty.

Is the replacement complete?

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Go to Step 16

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1. Using the scan tool, establish communication with the instrument cluster (IPC).
2. From the data inputs menu, select park brake input.
3. Momentarily connect a fused jumper from the park brake release solenoid connector terminal C to ground, then disconnect the jumper.

Does the cluster park brake input, as observed on the scan tool, switch on and off as the jumper is connected, then removed?

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Go to Step 14

Go to Step 12

Check CKT 1134 (LT BLU) for a short to ground.

Is the circuit OK?

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Go to Brake Warning System Check in Hydraulic Brakes

Go to Step 13

Repair CKT 1134 (LT BLU).

Is the circuit repair complete?

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Go to Step 16

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1. Check for poor terminal contact at park brake release solenoid connector terminals A and B.
2. If OK, replace park brake release solenoid.

Is the replacement complete?

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Go to Step 16

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1. Check rear integration module (RIM) connector C2 for poor terminal contact.
2. If OK, replace RIM. Refer to Body Control Module Replacement in Body Control System.

Is the replacement complete?

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Go to Step 16

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1. Make sure any components removed during diagnosis are installed in place and that all connectors are connected.
2. Repeat the system check. Refer to Park Brake Diagnostic System Check .

Is the system check complete?

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System OK

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