Was the Park Brake System Check performed?

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Go to Step 2

Go to Park Brake System Check

Attempt to release the park brake using the manual release.

Does the park brake release?

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Go to Step 3

Go to Step 4

1. Turn the ignition switch to ON.
2. Connect a scan tool to the data link connector (DLC) and turn the ignition switch to ON.
3. Establish communication with the rear integration module (RIM).
4. Observe the Park Brake Switch status.

Is the Park Brake Switch status on?

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Go to Step 5

Go to Step 18

Replace the park brake assembly. Refer to Parking Brake Lever Pedal Assembly Replacement .

Did you complete the replacement?

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Go to Step 29

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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 park brake release solenoid connector terminal B to ground.
7. Using the scan tool, command the park brake relay B (park brake release relay) on and off.
8. Connect the DMM between park brake release solenoid connector terminal A and ground.
9. Using the scan tool, command the park brake relay A (park brake ratchet relay) on and off.

Does the voltage measure near the specified value for both solenoid A and solenoid B tests?

Battery Positive Voltage (B+)

Go to Step 4

Go to Step 6

In step 6, was the voltage near the specified range for the test of solenoid A only?

Battery Positive Voltage (B+)

Go to Step 13

Go to Step 12

1. Remove park brake relay A from the rear fuse block.
2. Connect a DMM from the rear fuse block connector C2 terminal B1 to battery positive voltage (B+).
3. Using the scan tool as in step 6, command the park brake relay A (park brake ratchet relay) on, then off.

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

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Go to Step 10

Go to Step 8

Check CKT 1607 (PNK) for an open or short to battery voltage.

Did you find and correct the condition?

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Go to Step 29

Go to Step 28

Test the PRK/BRK voltage circuit for an open.

Did you find and correct the condition?

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Go to Step 29

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Check for an open on CKT 1628 (BLK).

Did you find and correct the condition?

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Go to Step 29

Go to Step 11

1. Check park brake relay A socket for poor terminal contact.
2. If OK, replace the park brake relay A .

Did you complete the replacement?

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Go to Step 29

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In step 6, was the voltage within the specified range for the test of solenoid B only?

Less than 0.5 V

Go to Step 7

Go to Step 22

1. Remove park brake relay B from the rear fuse block.
2. Connect a DMM from the rear fuse block connector C2 terminal B3 to battery positive voltage (B+).
3. Using the scan tool as in step 6, command the park brake relay B (park brake release relay) on, then off.

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

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Go to Step 16

Go to Step 14

Check CKT 1605 (LT GRN/BLK) for an open or short to battery voltage.

Did you find and correct the condition?

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Go to Step 29

Go to Step 28

Measure voltage at PRK/BRK fuse cavity RA1.

Does the voltage measure near the specified range?

Battery Positive Voltage (B+)

Go to Step 28

Go to Step 9

Check CKT 1627 (LT GRN) for an open.

Did you find and correct the condition?

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Go to Step 29

Go to Step 17

1. Check park brake relay B socket for poor terminal contact.
2. If OK, replace the park brake relay B.

Did you complete the replacement?

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Go to Step 29

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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 switch connector terminal A to ground, then disconnect the jumper.

Does the instrument cluster park brake input, as observed on the scan tool, change state as the jumper is connected, and then removed?

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Go to Step 21

Go to Step 19

Check CKT 1134 (LT BLU) for an open or short to ground.

Did you find and correct the condition?

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Go to Step 29

Go to Step 20

1. Check for poor terminal contact at IPC cluster connector C2 terminal B1.
2. If OK, replace the IPC cluster.

Did you complete the replacement?

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Go to Step 29

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1. Check for poor terminal contact at park brake release switch connector.
2. If OK, replace park brake release switch.

Did you complete the replacement?

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Go to Step 29

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Check PRK BRK fuse in rear fuse block.

Is the fuse open?

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Go to Step 23

Go to Step 15

1. Check for short at PRK BRK fuse within rear fuse block.
2. If OK check CKT 1627 and CKT 1628 for short to ground.

Did you find and correct the condition?

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Go to Step 29

Go to Step 4

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 13

Go to Step 5

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 20

Go to Step 22

1. Turn the ignition switch to ON.
2. Without removing relays, using a DMM to ground, check for power at park brake relay B terminal 86 and park brake relay A terminal 85.

Does the voltage measure near the specified range in both cases?

Battery Positive Voltage (B+)

Go to Step 28

Go to Step 27

Repair ignition circuit which feeds the park brake relay coils. Refer to Wiring Repairs

Did you complete the repair?

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Go to Step 29

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

Did you complete the replacement?

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Go to Step 29

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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 System Check

Is the system check complete?

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System OK

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