Idle Speed Control (ISC) Valve
- Listen for "clicking" sound after engine is shut off. If no sound is heard, disconnect ISC valve connector.
- Note terminal identification. See Fig 1. Using an ohmmeter, check resistance between designated terminals. See ISC VALVE RESISTANCE SPECIFICATIONS table.ISC VALVE RESISTANCE SPECIFICATIONS
Terminals Ohms B1 - S1 or S 10-30 B2 - S2 or S4 10-30 - To check valve operation, apply battery voltage to terminal "B1" and terminal "B2". See Fig 1. Repeatedly ground terminals "S1", "S2", "S", "S4" and "S1" in sequence. Note that valve closes. See Fig 1.
- Apply battery voltage to terminals "B1" and "B2". Repeatedly ground terminals "S4", "S", "S2", "S1" and "S4" in sequence. Note that valve opens. Replace valve if it failed to operate properly.