Idle Speed Control (ISC) By-Pass Solenoid
- Ensure ignition is off. Disconnect ISC solenoid connector. Set DVOM to 200-ohm scale. Measure resistance across ISC solenoid terminals. If resistance is 7-13 ohms in one direction and higher in the opposite direction (because of diode), solenoid is okay.
- Set DVOM to 20 k/ohm scale. Measure resistance from either ISC solenoid terminal to ISC solenoid housing. If resistance is greater than 10 k/ohms, ISC solenoid is okay.