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Test HB: Idle Switch: Testing

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

NOTE: TP switch is also referred to as idle switch.

1) DTC P0510: Check Idle Switch Continuity
DTC P0510 indicates PCM has received battery voltage from closed TP switch and a signal from TP sensor which indicates throttle valve is open. Possible causes are as follows:
- Closed TP switch IDLE circuit is open or shorted to power.
- Closed TP switch.
- Faulty TP sensor.
Turn ignition off. Disconnect idle switch harness connector. Ensure throttle is closed. Using DVOM, measure resistance between IDLE terminal and IGN terminal on idle switch. See Figure. If resistance is less than 50 ohms, go to next step. If resistance is 50 ohms or more, replace idle switch.

2) Check IDLE Circuit For Open

Ensure ignition is off. Disconnect PCM harness connector. Using DVOM, measure resistance of IDLE circuit (Brown/Yellow wire) between idle switch harness connector and PCM connector. See Figure and Figure . If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in IDLE circuit. See WIRING DIAGRAMS article.

3) Check IDLE Circuit For Short To Ground

Using DVOM, measure resistance between negative battery terminal and IDLE circuit at PCM harness connector. See Figure. If resistance is more than 10 k/ohms, go to next step. If resistance is 10 k/ohms or less, repair short to ground in IDLE circuit.

4) Check IDLE Circuit For Short To Power

Using DVOM, measure resistance between IDLE and VPWR circuits at PCM harness connector. See PCM TERMINAL CIRCUIT IDENTIFICATION table. See Figure and Figure . If resistance is more than 10 k/ohms, replace PCM. If resistance is 10 k/ohms or less, repair short to power in IDLE circuit. See WIRING DIAGRAMS article.