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Component Tests and General Diagnostics

Multiplex Control Unit Input Test

1. Remove the driver's dashboard lower cover.




2. Disconnect the under-dash fuse/relay box connectors C, E, F, J, K, O, P, Q, X and Y.

NOTE: All connectors are wire side of female terminals.

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 connectors 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 5.

Part 1:




Part 2:




5. Reconnect the connectors to the under-dash fuse/relay box, and make sure these input tests at the appropriate connectors on the underdash fuse/relay box.
- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, the multiplex control unit must be faulty, replace the under-dash fuse/relay box assembly.