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 PCM connector D (17P) and cruise control unit 14P connector.




5. Check for continuity between PCM connector terminal D12 and body ground.

Is there continuity?

YES - Repair short to ground in the wire between PCM connector terminal D12 and the cruise control unit 14P connector terminal No.8.

NO - Go to step 6.

6. Reconnect PCM connector D (17P) and the cruise control unit 14P connector.




7. 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 8.

NO - Replace the cruise control unit.




8. Connect a voltmeter between PCM connector terminal D12 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. If necessary replace the PCM and recheck.

NO - Repair open in the wire between PCM connector terminal D12 and the control unit 14P connector terminal No.8.