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Wiper and Washer Systems: Testing and Inspection

Control Unit Input Test

1. Before testing the wiper/washer 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, and disconnect its connector.




3. Inspect all 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 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.

Multiplex Control Unit, Passenger's:

5. Remove the passenger's under-dash fuse/relay box.
6. Remove the passenger 5 multiplex control unit from the passenger's under-dash fuse/relay box, and disconnect its connector.




7. Inspect all 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 8.




8. With the passenger's multiplex control unit still disconnected, make these input tests at the connector 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, the control unit must be faulty; replace it.