1. Set the park brake switch to the APPLY position.
2. Observe the park brake pump motor operation.

Does the park brake pump motor run?

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Go to Step 2

Go to Park Brake Pump Motor Does Not Run

Check actuator movement during park brake pump motor operation.

Does the actuator extend normally?

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Go to Park Brake Pressure Sensor Circuit Check

Go to Step 3

1. APPLY, then RELEASE the park brake switch.
2. Verify that the park brake pressure solenoid valve clicks.

Does the solenoid click?

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Go to DTC 09 Park Brake System Pressure Leak-Down

Go to Step 4

1. Disconnect the park brake pressure solenoid valve connector.
2. Turn the ignition switch to the RUN position.
3. Connect a test lamp between terminals A and B in the park brake pressure solenoid valve harness connector.

Does the test lamp light?

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Go to Step 8

Go to Step 5

Connect a test lamp between terminal A in the park brake pressure solenoid valve harness connector and chassis ground.

Does the test lamp light?

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Go to Step 6

Go to Step 7

Locate and repair open in CKT 150 (BLK) between G101 (Diesel), or G111 (Gas) and terminal A in the park brake pressure solenoid valve harness connector.

Is the repair complete?

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System OK

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Locate and repair open in CKT 1931 (YEL/BLK) between S232 and terminal A in the park brake pressure solenoid valve harness connector.

Is the repair complete?

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System OK

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Replace park brake pressure solenoid valve. Refer to Park Brake Solenoid Valve Replacement .

Is the repair complete?

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System OK

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