Headlamp Control Module: Testing and Inspection
Control Unit Input Test1. Before testing exterior light control functions, troubleshoot the multiplex control system.
Multiplex Control Unit, Driver's:
2. Remove the driver's unit from the [1][2]driver's under-dash fuse/relay box.
3. Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 4.
4. Make these input tests at the connector or fuse/relay box socket.
- If any test indicates a problem, find and correct the cause, then recheck the system. If all the in put tests prove OK, go to step 5.
Multiplex Control Unit, Door:
5. Remove the driver's door panel, and disconnect the 20P connector from the door unit.
6. Inspect the connector and socket terminals to be sure they are all making good contact.
- If the terminals are bent, loose or corroded, repair them as necessary, and recheck the system.
- If the terminals look OK, go to step 7.
7. Reconnect the connectors to the unit, and make this input test.
- If a test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 8.
8. If all the input tests prove OK, one of the control units must be faulty. Substitute a known-good control unit for the one that is most likely at fault, then recheck the system. If the system works properly, the original control unit is faulty; replace it. If there is still a malfunction, substitute a known-good control unit for the next most likely unit to be at fault, and recheck. If the system works properly, the original unit is faulty; replace it.