Automatic Transmission

Ignition And Inhibitor Switch Circuit:

To test the start signal, proceed as follows.
1. Place the transmission in PARK or NEUTRAL.
2. Turn the key to the START position.
3. Using a voltmeter, check the voltage between ECM harness terminal 51 and ground.

Voltage:
System Voltage.

4. Place the transmission in PARK or NEUTRAL.
5. Turn the key to the START position.
6. Using a ohmmeter, check for continuity between ECM harness terminal 71 and ground.

Continuity:
Should exist.

If any of the previous tests produce unsatisfactory results, Check the inhibitor switch. The harness may need to be repaired or replaced. Once repairs have been completed, road test the vehicle to confirm that the repair has corrected the problem.

If the same problem reoccurs, it is possible that there is an intermittent failure of the component or the ECM. Check for looseness at all harness junctions and test for an intermittent failure.