Idle Speed Controller (ISC) Valve
- Check wiring and controller for damage or deterioration. Repair as necessary. Connect test light to idle speed actuator between Red wire and ground. Turn ignition on. If light is on, go to next step. If light is off, repair open in power feed circuit.
- Connect jumper wire from actuator Gray wire to ground and turn ignition on. If speed controller operates, go to next step. If not, replace idle speed controller.
- Using an ohmmeter check for continuity between wire at ECA pin No. 21 and Gray wire at controller. If no continuity, repair wiring. If continuity present, idle speed controller circuit is okay.