Idle Speed Control (ISC) Valve
- After stopping engine, clicking sound should be heard from ISC valve. If not, remove ISC valve and perform operation check.
- Drain engine coolant. Disconnect 2 electrical connectors, 2 coolant by-pass hoses and air hoses. Remove 2 bolts and ISC valve body.
- Apply battery voltage to dual-terminal connector. Grounding terminals "S1", "S2", "S" and "S4" in sequence should cause valve to close. See Fig 1. With battery voltage still connected, grounding terminals in reverse sequence ("S4", "S", "S2" and "S1") should cause valve to open. If not, perform resistance check.
- Check resistance values of ISC valve. Check resistance with ignition off and ISC electrical connector disconnected. If resistance is not as specified in chart, replace ISC valve.
ISC VALVE RESISTANCE SPECIFICATIONS
| Terminals | Ohms |
|---|---|
| B1 - S1 Or S | 10-30 |
| B2 - S2 Or S4 | 10-30 |