Air Control Valve Circuit
- The Engine Control Module (ECM) controls the Air Control Valve (ACV) to maintain near atmospheric pressure at front and rear bearings on supercharger. This prevents grease and oil from leaking from the supercharger, due to pressure fluctuation inside the supercharger.
- Check air control valve operation. See AIR CONTROL VALVE under SUPERCHARGER. Replace air control valve if defective. If air control valve operates correctly, access the ECM, located below driver's seat.
- Turn ignition on. Using voltmeter, check voltage between terminal No. 20 (Red/White wire) on ECM and chassis ground. See Fig 1.
- Voltage should be 9-14 volts. If voltage is not within specification, check for defective EFI main relay or wiring harness between EFI main relay and ECM. See EFI MAIN RELAY under RELAYS. See appropriate wiring diagram in WIRING DIAGRAMS
article.
- If EFI main relay and wiring harness are okay, check ECM ground circuit. If ECM ground circuit is okay, substitute another ECM and recheck system operation.
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