ISC Servo Motor
- Turn ignition switch to "OFF" position. Disconnect ISC servo connector. Check motor coil continuity between terminals No. 1 and 4. See Figure . Resistance should read between 7 and 10 ohms. If resistance is zero ohms or abnormally large, open or short circuit exists in motor coil. Replace ISC servo assembly.
- Reconnect ISC servo connector. Attach a voltmeter to terminals No. 1 and 4. After the ignition is turned on, voltmeter should read 1.5 volts for 15 seconds. After 15 seconds, voltmeter reading should drop to .9 volts.
- Make sure there is no continuity between terminals No. 1 or 4 and injection mixer body. If continuity exists, there is a short circuit in coil. Replace ISC servo assembly.