Control Unit Input Test
- Remove the bulkhead panel, then disconnect the connectors from the ECM. 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, make the following input tests at the connector. See Fig 1 and Fig 2 . If any test indicates a problem, find and correct the cause, then recheck the system. If all the input tests prove OK, the ECM must be faulty; replace it.