Component Tests and General Diagnostics

Multiplex Control Unit Input Test

NOTE: If the multiplex control unit is replaced, never use a multiplex control unit other than the one which is manufactured by the original multiplex control unit maker. Using other multiplex control units, manufactured by a non-original maker could cause a malfunction of communication among the multiplex control unit.

Door Unit:

1. Remove the driver's door panel, and disconnect the connectors from the door multiplex control unit.
2. 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 3.







3. Make the following input tests at connector A.
- 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 4.

Passenger's Unit:

4. Remove the passenger's multiplex control unit from the passenger's under-dash fuse/relay box.
5. 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 6.




6. Make the following input tests at connector B and the fuse/relay box socket.
- 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 7.

Driver's Unit:

7. Remove the driver's multiplex control unit from the driver's under-dash fuse/relay box.
8. 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 9.




9. Make the following input tests at connector B and the fuse/relay box socket.
- If a test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, troubleshoot the Multiplex Control System.