2. Inspect the connectors and contacts of the sockets to make sure they are in good contact.
- If the pins are bent, loose or corroded, repair them and check the system again.
- If the pins are OK, perform the following tests on the input signal at the connector.
- If any of the tests indicate a problem, find and correct the cause, then test the system again.
- If all input signal tests are positive, the control unit is faulty, replace.