GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2002 🢒 Isuzu T-Series (Truck Line C) 🢒 DTC 🢒 DTC 008

Circuit Description

In order to release the parking brake, the pump motor must supply fluid pressure to the actuator. When this pressure overcomes the spring tension inside of the actuator, the actuator piston moves, releasing the parking brake. The park brake pressure sensor monitors the fluid pressure whenever the ignition is ON.

Conditions for Running the DTC
    • The ignition is ON.
    • The parking brake applied.

Conditions for Setting the DTC

The parking brake pressure sensor detects system pressure when the parking brake is applied.

Action Taken When the DTC Sets
    • The SERVICE PARK BRAKE indicator turns ON.
    • Electro-hydraulic park brake function may be disabled.

Conditions for Clearing the DTC

The conditions for setting the DTC are no longer present and you use the procedure specified in Diagnostic Trouble Code (DTC) Clearing .

Diagnostic Aids

Thoroughly inspect connections or circuitry that may cause an intermittent malfunction. Refer to the following:

    •  Testing for Electrical Intermittents
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Connector Repairs

Step

Action

Yes

No

Schematic Reference: Park Brake System Schematics

1

Did you perform the Park Brake Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Park Brake

2
  1. Engage the park brake.
  2. Observe the park brake pump motor.

Does the park brake pump motor continue to run?

Go to Park Brake Pump Motor Runs Continuously

Go to Step 3

3
  1. Disconnect the park brake pressure solenoid valve.
  2. Test the park brake pressure solenoid valve control circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 4

4

Test the park brake pressure solenoid valve ground circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

5

CAUTION:: This system operates using fluid pressure up to 12 400 kPa (1800 psi). Some malfunctions can cause this pressure to be trapped in the system. Use caution when loosening pipe fittings on a system that does not work or personal injury can result.

  1. Slowly loosen the pipe fitting between the actuator and the park brake pressure solenoid valve.
  2. Observe if any fluid is leaving the fitting.

Is any fluid leaving the fitting?

Go to Step 6

Go to Park Brake Pressure Sensor Circuit Check

6

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

Did you complete the repair?

Go to Step 7

--

7
  1. Reconnect all the connectors.
  2. Clear DTCs. Refer to Diagnostic Trouble Code (DTC) Clearing .
  3. Operate the park brake.
  4. Verify that no DTCs reset. Refer to Diagnostic Trouble Code (DTC) Displaying .

Did the same DTC reset?

Go to Step 2

Go to Step 8

8

Did any DTCs reset?

Go to Diagnostic Trouble Code (DTC) List

System OK