Voltage Signal: Testing and Inspection

Back-up And Voltage Signal Circuit:

1. Using a volt meter, check the Voltage between engine control module harness terminal 103 and ground.

Voltage should equal system Voltage.

2. Disconnect the negative battery cable and the engine control module connector.
3. Using an ohm meter, check for continuity between the positive battery terminal and engine control module harness terminal 103.

Continuity should exist.

4. Using an Ohmmeter, check for continuity between chassis ground (not the negative battery terminal) and engine control module harness terminal 103.

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 engine control module. Check for looseness at all harness junctions and test for an intermittent failure.