Operation CHARM: Car repair manuals for everyone.

Communication Circuit Troubleshooting

Cruise Control Communication Circuit Troubleshooting

1. Start the engine.
2. Turn on the cruise control main switch, then drive the vehicle to speeds over 25 mph (40 km/h) with the cruise control.

Does the cruise control operate?

YES - Go to step 3.

NO - Check the cruise control unit. or cruise control actuator.

3. Turn the ignition switch OFF.
4. Disconnect Powertrain Control Module (PCM) connector A (32P) and cruise control unit 14P connector.




5. Check for continuity between the PCM connector terminal AS and body ground.

Is there continuity?

YES - Repair a short to ground in the wire between the PCM connector terminal A5 and the cruise control unit 14P connector terminal No.8.

NO - Go to step 8.

6. Reconnect PCM connector A (32P) and cruise control unit 14P connector.
7. Turn the ignition switch ON (II).




8. Connect a voltmeter between cruise control unit 14P connector terminal No.8 and body ground. Test-drive the vehicle at speeds over 25 mph (40 km/h) with the cruise control set, and watch the voltmeter.

Is there about 1 V?

YES - Go to step 9.

NO - Substitute a known-good control unit. If the system works properly, replace the cruise control unit.




9. Connect a voltmeter between PCM connector terminal A15 and body ground. Drive the vehicle at speeds over 25 mph (40 km/h) with the cruise control set, and watch the voltmeter.

Is there about 1 V?

YES - Check for loose connections of the BLU/GRN wire between the cruise control unit and the PCM. If necessary replace the PCM and recheck.

NO - Repair or open in the BLU/GRN wire between the AS terminal and the cruise control unit.