Power Source Check
NOTE:
Proceed with following tests only if directed from TROUBLE SHOOTING , Type "A" or Type "B" diagnostic codes. If cruise control system is diagnosed out of sequence, replacement of good components could result.
- Turn ignition on. Check "ECU-IG" fuse. If fuse is blown, replace fuse and recheck system. If fuse blows again, check for short in Black/Red wire between fuse and terminal of main switch. See Fig 1. See WIRING DIAGRAMS . If fuse is okay, go to next step.
- Check for continuity between main switch terminal 3 and body ground. If continuity is not present, check for open in White/Black wire between terminal 3 of main switch and ground. See Fig 1. See WIRING DIAGRAMS . If continuity is present, go to next step.
- Check for voltage between main switch connector terminal 2 (Blue/Red wire) and ground. See Fig 1. If battery voltage is present go to next step. If battery voltage is not present, check for open in Blue/Red wire between main switch terminal 2 and ECU-IG fuse. See WIRING DIAGRAMS .
- Turn main switch ON, and check for battery voltage between main switch terminal 6 (Red wire) and body ground. See Fig 1. If battery voltage is present, go to next step. If battery voltage is not present, go to step 7).
- Turn main switch OFF, and check for battery voltage between main switch terminal 6 (Red wire) and body ground. Battery voltage should not be present. If battery voltage is not present, go to next step. If battery voltage is present, go to step 7).
- Jumper main switch terminal 4 (Green/White wire) to ground with main switch connector connected. Indicator light should illuminate with main switch turned ON. Indicator light should not illuminate with main switch turned OFF. If light operates as specified, go to step 8). If light does not operate as specified, go to next step.
- With main switch connector connected, jumper from positive battery lead to terminal 2, and jumper negative battery lead to terminal 3. See Fig 1. Check that there is continuity between terminals 2 and 6 with the main switch turned ON. Check that there is no continuity between terminals 2 and 6 with the main switch turned OFF. If continuity is not as specified, replace switch.
- Disconnect cruise control computer connector. Check for continuity between computer connector terminal 13 (Brown wire) and ground. See Fig 2. If continuity is not present, check for open in Brown wire between computer connector and ground. If continuity is present, go to next step.
- Check for battery voltage between computer connector terminal 10 (Red wire) and body ground with main switch turned ON. If battery voltage is not present, repair open in Red wire between computer and main switch. If battery voltage is present, go to next step.
- With cruise control computer connector disconnected, jumper connector terminal 3 (Green/White wire) to ground. See Fig 2. Main switch indicator light should illuminate with main switch turned ON. If light does not illuminate, repair open in Green/White wire between cruise control computer and main switch. If light illuminates, go to next step. See WIRING DIAGRAMS .
- Disconnect main switch connector, and check for continuity between COMPUTER connector terminal 3 (Green/White wire) and ground. See Fig 2. If continuity is present, repair short to ground in Green/White wire between computer and main switch. See WIRING DIAGRAMS . If continuity is not present, and cruise control still does not operate, replace cruise control computer.