Control Unit

Keyless Entry/Security Alarm System

Control Unit Input Test

1. Before testing the keyless entry/security control functions, troubleshoot the multiplex control system.

Multiplex Control Unit, Driver's

2. Remove the driver's multiplex control unit from the 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. With the driver's multiplex control unit still disconnected, make these input tests at the connector and driver's under-dash fuse/relay box sockets.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 5.




5. Reconnect the driver's multiplex control unit to the driver's under-dash fuse/relay box, and perform the following input tests at the appropriate connectors on the back of the driver's under-dash fuse/relay box. For driver's under-dash fuse/relay box connector socket location.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 6.

Multiplex Control Unit, Passenger's:

6. Remove the passenger's multiplex control unit from the passenger's under-dash fuse/relay box, and disconnect its connector.




7. 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 8.




8. With the passenger's multiplex control unit still disconnected, make these input tests at the connectors and the passenger's under dash fuse/relay box sockets
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 9.




9. Reconnect the passenger's multiplex control unit to the passenger's under dash fuse/relay box, and perform the following input tests at the appropriate connectors on the passenger's under dash fuse/relay box If a second key is not available for the key cylinder tests, make a non immobilizer copy For passenger's under-dash fuse/relay box connector socket location.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 10.

Multiplex Control Unit, Door

10. Remove the door multiplex control unit, and disconnect its connector.




11. Inspect the connector and socket terminals to be sure they are 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 12.




12 With the door multiplex control unit still disconnected, make these input tests at the connector.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 13.




13. Reconnect the connector to the door multiplex control unit, make these input tests at the connector.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, go to step 14.

14. 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.