Voltage Signal: Testing and Inspection

Power Supply Circuit:

Engine Control Module Connector--For Pin Applications See Components:

1. Disconnect the negative battery cable and the MFI relay connector. Using a Volt meter check the Voltage between MFI relay connector terminal 8 and ground.

Voltage System Voltage.

2. Disconnect the negative battery cable, the MFI relay connector and the ECU connector.
3. Using an Ohm meter, check for continuity between MFI relay connector terminal 3 and ECU harness terminals 12 and 25.
Continuity Should exist.

4. Using an Ohm meter, check for continuity between chassis ground (not the negative battery terminal) and ECU harness terminals 12 and 25 and MFI relay connector terminal 3.
Continuity Should not exist.

If any of the previous tests produce unsatisfactory results, the harness will need to be repaired or replaced. Once repairs have been completed, confirm that the repair has corrected the problem.

If the trouble returns, it is possible that there is an intermittent failure of the component or the ECU. Check for looseness at all harness junctions and test for an intermittent failure.