Inspection and Verification
- Verify the customer concern.
- Visually inspect the following for obvious signs of mechanical or electrical damage.VISUAL INSPECTION CHART
Mechanical Electrical - Throttle body
- Battery junction box (BJB) fuse 42 (15A)
- Circuitry
- Speed control switch
- Speed control deactivator switch
- Stoplamp switch
- Powertrain control module (PCM)
- If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
- Verify the speedometer operates correctly without speed control by test driving the vehicle. If the speedometer does not operate correctly, refer to INSTRUMENT CLUSTER .
- Verify the stoplamp operate correctly with the ignition switch in the ON position. If the stoplamp do not operate correctly, refer to EXTERIOR LIGHTING .
- Verify the parking brake warning indicator is operating correctly. If the parking brake warning indicator does not operate correctly, refer to INSTRUMENT CLUSTER .
- If the cause is not visually evident, connect the scan tool to the data link connector (DLC).
- If the scan tool does not communicate with the VCM:
- Check the VCM connection to the vehicle.
- Check the scan tool connection to the VCM.
- Refer to MODULE COMMUNICATIONS NETWORK , No Power To The Scan Tool, to diagnose no communication with the scan tool.
- If the scan tool does not communicate with the vehicle:
- Verify the ignition key is in the ON position.
- Verify the scan tool operation with a known good vehicle.
- Refer to MODULE COMMUNICATIONS NETWORK to diagnose no response from the powertrain control module (PCM).
- Carry out the network test:
- If the scan tool responds with no communication for one or more modules, refer to MODULE COMMUNICATIONS NETWORK .
- If the network test passes, retrieve and record the continuous memory DTCs.
- Clear the continuous DTCs and carry out the self-test diagnostics for the SJB.
- If the DTCs retrieved are related to the concern, go to the Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) Chart. For all other DTCs, refer to MULTIFUNCTION ELECTRONIC MODULES .
- If no DTCs related to the concern are retrieved, go to Symptom Chart .
NOTE:
Make sure to use the latest scan tool software release.
NOTE:
The vehicle communication module (VCM) LED prove-out confirms power and ground from the DLC are provided to the VCM.
POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) CHART
| DTC | Description | Action |
|---|---|---|
| P0500 | Vehicle Speed Sensor | REFER to the Introduction - Gasoline Engines . |
| P0579 | Cruise Control Multi-function Input A Circuit Range/Performance | Go to Pinpoint Test C . |
| P0581 | Cruise Control Multi-function Circuit High | Go to Pinpoint Test C . |
| P1572 | Brake Pedal Switch Circuit | Go to Pinpoint Test B . |
| P1703 | Brake Switch Out of Self Test Range | Go to Pinpoint Test B . |
| All other DTCs | - | REFER to the Introduction - Gasoline Engines . |