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.

[1][2]Multiplex Control Unit, Driver's

2. Remove the driver's [1][2]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 [1][2]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 [1][2]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.

[1][2]Multiplex Control Unit, Passenger's

6. Remove the passenger's [1][2]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 [1][2]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 [1][2]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 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.

[1][2]Multiplex Control Unit, Door

10. Remove the door [1][2]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 [1][2]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 [1][2]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.