Ignition Signal With A/T

ECU System:

To test the Ignition Signal to the ECU, locate pins #4 and #9 of ECU connector C50-3, and test for battery voltage with the ignition key in the "on" position. Both pins should have battery voltage present.

NOTE: To test pins do not remove the connector from the ECU, instead insert a straight pin or needle from the back side of the connector to access the pin.

Gear Selector Position Switch (Inhibitor Switch) Circuit:

Gear Selector Position Switch (Inhibitor Switch) location:

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 108 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 8.

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.