FixVault

ISC Servo Motor

  1. 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.
  2. 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.
  3. 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.