Ignition Switch-ST and Park/Neutral (Inhibitor) Switch (A/T)

Ignition Switch-ST 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 ECU harness terminal 8 and ground.

Voltage:
System Voltage.

4. Place the transmission in PARK or NEUTRAL.
5. Turn the key to the OFF position.
6. Disconnect the negative battery terminal and disconnect the ECU connectors.
7. Place the transmission in NEUTRAL.
8. Using a ohmmeter, check for continuity between ECU harness terminals 2 and 108.

Continuity:
Should exist.

9. Place the transmission in PARK.
10. Using a ohmmeter, check for continuity between ECU harness terminals 2 and 8.

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 ECU. Check for looseness at all harness junctions and test for an intermittent failure.