Troubleshooting Hints

IMPORTANT: The Powertrain Control Module (PCM) will inhibit cruise control when there is a malfunction in any of the cruise control inhibit criteria. The PCM will inhibit cruise control when:
^ Vehicle speed is less than 40 km/h (25 mph).
^ PARK, REVERSE, NEUTRAL, or 1st GEAR is indicated by the PRNDL encoder.
^ An over/under battery voltage condition exists.
^ Low engine RPM.
^ High engine RPM (fuel cut-off).

1. Check all cruise control inhibit criteria.
2. Check for Diagnostic Trouble Codes (DTCs). Refer to Engine Controls. Testing and Inspection
3. Check STOP LAMP Fuse. If open, check circuit 140 for a short to ground.
4. Check CRUISE Fuse. If open, check circuit 739 for a short to ground.
5. Check that cruise control module linkage is connected and moving freely.
6. Check stop lamp switch for proper adjustment/ alignment. Refer to Brakes. Brake Light Switch
^ Make sure that center high-mounted stop lamp is working. If inoperative, cruise module will be disabled.
^ Check for a broken (or partially broken) wire inside of the insulation which could cause system malfunction but prove GOOD in a continuity/voltage check with a system disconnected. These circuits may be intermittent or resistive when loaded, and if possible, should he checked by monitoring for a voltage drop with the system operational (under load).
^ Check for proper installation of aftermarket electronic equipment which may affect the integrity of other systems. Refer to General Troubleshooting Procedures. Diagnostic Aids
^ Refer to System Diagnosis.