Test A
- Turn ignition on. Disconnect cruise control ECU 15-pin connector. Connect voltmeter positive lead to cruise control ECU harness connector terminal No. 1 (White/Yellow) and negative lead to ground. Battery voltage should exist when cruise control switch is turned on, no voltage should exist when turned off. If voltage is as specified, go to next step. If voltage is not as specified, inspect E2 fuse (10-amp), repair White/Yellow wire or Green/Light Green wire, or replace cruise control switch.
- With engine running, turn cruise control switch on. Using voltmeter, check voltage between cruise control ECU harness connector terminal No. 9 (Purple/Green wire) and ground. With brake/clutch switch released, battery voltage should be present. With brake/clutch switch depressed, battery voltage should not be present. If voltage is as specified, go to TEST C. If voltage is not as specified, go to next step.
- Ensure engine is running and cruise control system is on. Disconnect brake switch vent valve. Using a voltmeter, check voltage between brake switch harness connector terminal No. 1 (Purple/Yellow wire) and ground. Battery voltage should be present with clutch switch released. With brake switch depressed, no voltage should exist. If voltage is as specified, repair Purple/Green wire or replace brake switch vent valve. If voltage is not as specified, go to next step.
- Ensure engine is running and cruise control system is on. Disconnect clutch switch harness connector, and check voltage between terminal No. 2 (Purple wire) and ground. Battery voltage should exist with clutch switch released, and no voltage should exist with clutch switch depressed. If voltage is as specified, repair Purple/White wire or replace clutch switch. If voltage is not as specified, go to next step.
- Ensure engine is running and cruise control system is on. Disconnect speed trip module relay. Using a voltmeter, check voltage between ground and speed trip module relay harness connector terminals No. 30 (White/Blue wire) and No. 87 (White/Gray wire). If battery voltage is present, go to next step. If battery voltage is not present, repair White/Blue wire, White/Gray wire, or replace resistor or diode.
- Turn ignition off. Disconnect speed trip module relay. Connect ohmmeter positive lead to speed trip module relay connector terminal No. 86 (Purple/White wire) and negative lead to terminal No. 87 (White/Grey wire). If resistance is less than one ohm, repair Purple/White wire. If resistance is greater than one ohm, replace speed trip module relay.