Diagnostic Test

CHECK FOR AN ACTIVE DTC
1. Perform any Service Bulletins that may apply.
2. Turn the ignition on.
3. With the scan tool, read ABS DTCs and record on the repair order.
4. With the scan tool, erase ABS DTCs.
5. Start the engine.
6. Press and release the brake pedal.
7. With the scan tool, read ABS DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the ABS-INTERMITTENT CONDITION TEST. Refer to ABS INTERMITTENT CONDITION .
VACUUM PRESSURE SENSOR LEAKS
1. Visually inspect the vacuum lines to the Vacuum Pressure Sensor for leaks.
2. Check the Vacuum Pressure Sensor mounting seal at the power brake booster for correct installation.
  Were any problems found?
  
  Yes
  - Repair as necessary.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 3
(F856) 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off.
2. Disconnect the Vacuum Pressure Sensor harness connector.
3. Disconnect the PCM C2 harness connector.
4. Connect the adapter.
  (special tool #10436, Adapter, GPEC Diagnostic)
5. Measure the resistance of the (F856) 5-Volt Supply circuit between the Vacuum Pressure Sensor harness connector and the GPEC Adaptor.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (F856) 5 Volt Supply circuit for an open or high resistance.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 4
(K900) SENSOR GROUND OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (K900) Sensor Ground circuit between the Vacuum Pressure Sensor harness connector and the GPEC Adaptor.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (K900) Sensor Ground circuit for an open or high resistance.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 5
(B32) VACUUM PRESSURE SENSOR SIGNAL OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (B32) Vacuum Pressure Sensor Signal circuit between the Vacuum Pressure Sensor harness connector and the GPEC Adaptor.
  Is the resistance above 5.0 Ohms?
  
  Yes
  - Repair the (B32) Vacuum Pressure Sensor Signal circuit for an open or high resistance.
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Go To 6
VACUUM PRESSURE SENSOR
1. Replace the Vacuum Pressure Sensor.
2. With the scan tool, erase ABS DTCs.
3. Start the engine.
4. Press and release the brake pedal.
5. With the scan tool, read ABS DTCs.
  Does the DTC remain active?
  
  Yes
  - Go To 7
  No
  - Test complete.
POWERTRAIN CONTROL MODULE (PCM)
1. Replace the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL .
2. With the scan tool, erase ABS DTCs.
3. Start the engine.
4. Press and release the brake pedal.
5. With the scan tool, read ABS DTCs.
  Does the DTC remain active?
  
  Yes
  - Replace the Anti-lock Brake System (ABS) Module in accordance with the Service Information. Refer to MODULE, ANTI-LOCK BRAKE SYSTEM (ABS), REMOVAL .
  - Perform the ABS VERIFICATION TEST. Refer to ABS VERIFICATION TEST .
  No
  - Test complete.