Communication Circuit Troubleshooting

Cruise Control Communication Circuit Troubleshooting (A/T)

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 cruise control unit 14P connector and PCM connector A (32P).




5. Check for continuity between the No. 8 terminal of the cruise control unit 14P connector and body ground.

Is there continuity?

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

NO - Go to step 6.

6. Reconnect the cruise control unit 14P connector and PCM connector A (32P).




7. Connect a voltmeter between the No. 8 terminal of the cruise control unit 14P connector 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 8.

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




8. Connect a voltmeter between PCM connector terminal A5 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 connectors of the BLU/GRN wire between the cruise control unit and PCM. If necessary replace the PCM and recheck.

NO - Repair open in the wire between the PCM connector terminal A5 and the cruise control unit 14P connector terminal No. 8.