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Home >> Nissan-Datsun >> 1994 >> 240SX Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Idle Control System >> Auxiliary Air Control (AAC) Valve System Test
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Auxiliary Air Control (AAC) Valve System Test

  1. Start engine and bring to operating temperature. Check idle speed. See SPECIFICATIONS article in the ENGINE PERFORMANCE section. Adjust idle speed if necessary. See ADJUSTMENTS article in the ENGINE PERFORMANCE section.
  2. Check for stored codes. See RETRIEVING CODES in TESTS W/CODES article in the ENGINE PERFORMANCE section. If Code 43 is present, repair cause of Code 43 before continuing. If Code 43 is not present, disconnect throttle position sensor harness connector. If idle speed does not drop, go to next step. If idle speed drops, system is functioning properly.
  3. Turn ignition off. Disconnect AAC valve harness connector. Turn ignition on. Measure voltage between ground and AAC valve harness connector Red/Green wire. Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check 10-amp fuse and 75-amp fusible link located in engine compartment fuse box. If fuse and fusible link are okay, repair or replace harness or connectors between AAC valve and fuse box.
  4. Turn ignition off. Disconnect ECM harness connector. Check continuity between ECM harness connector terminal No. 113 (Sky Blue wire) and AAC valve harness connector Red/White wire. Continuity should exist. If continuity exists, check AAC valve. See AUXILIARY AIR CONTROL (AAC) VALVE TEST. If AAC valve is okay, check ECM pin terminals and ECM harness connector terminals for damage or corrosion. Repair as necessary. If continuity does not exist, repair open in harness or connectors.
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