Diesel Data: Automotive Repair

Keyless/Power Door Locks/Security System (MICU) Input Test




Keyless/Power Door Locks/Security System (MICU) Input Test

NOTE: Before testing the MICU, troubleshoot the multiplex integrated control unit first, using B-CAN System Diagnosis Test Mode A Troubleshooting - B-CAN System Diagnosis Test Mode A.

1. Turn the ignition switch to LOCK (0).

2. Disconnect under-dash fuse/relay box connectors E, F, G, M, N, Q, R, and T.

NOTE: All connector views 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, do the following input tests.

- 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 connectors to the under-dash fuse/relay box, and do the following input tests.

- If any test indicates a problem, find and correct the cause, then recheck the system.
- If all the input tests prove OK, the MICU must be faulty; replace the under-dash fuse/relay box Under-dash Fuse/Relay Box Removal/Installation.