Momentary Interruption

During diagnosis, if Codes 13, 22, 24, 41 or 47 are stored in ECU memory and no trouble can be found with these circuits, it will be necessary to perform a momentary interruption test.

1. Clear codes from ECU memory. See CLEARING CODES in this article. With ignition off, connect a jumper wire between terminals E1 and TE1 of TDCL connector.
2. Start engine. Ensure CHECK engine light goes out. Pull lightly on wires and apply vibration to connectors and relays associated with diagnostic codes.
3. During this test if CHECK engine light illuminates, it indicates which connector or where in the wire harness there is a fault. Repair as necessary.
4. Clear diagnostic codes. Start engine. If CHECK engine light does not go out, check thoroughly for faulty connections. Perform MOMENTARY INTERRUPTION LS400 test again. If CHECK engine light still will not go out, see LS400 CONTROL UNIT in SYSTEM/COMP TESTS article.