Throttle Full Close Switch: Testing and Inspection

System Schematic:

To test the Idle Switch, located on the throttle body, proceed as follows.


1. Disconnect the ISC (Idle Speed Control) connector.
2. Make sure that the idle switch is depressed and check for continuity between terminal 2 and the body ground. If there is no continuity the ISC assembly must be replaced.


3. Depress the accelerator off the idle position and check for continuity, there should be none. Release the throttle to the idle position and test for continuity again, there should be continuity.

HARNESS TEST:

1. Disconnect the TPS connector and Turn on the ignition.
2. Using a voltmeter, measure the power supply voltage between the harness connector terminal 2 and ground.

Voltage: 4 Or More Volts.

3. If no voltage is present Check for continuity between ECU harness connector 7 and ISC harness connector 2.

Continuity: Should Exist

If any of the previous tests produce unsatisfactory results, the harness will 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.