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Home >> Infiniti >> 2003 >> QX4 4WD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Air Induction Systems >> Variable Induction Air Control System >> Diagnostic Procedure (FX45)
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Diagnostic Procedure (FX45)

  1. Check overall function. Start engine and warm it up to normal operating temperature, and proceed accordingly:
    • With CONSULT-II  - Perform VIAS SOL VALVE in ACTIVE TEST mode. Turn VIAS control solenoid valve ON and OFF, and ensure that power valve actuator rod moves. See Figure. If results are as specified, inspection is complete. If results are not as specified, go to next step.
    • Without CONSULT-II  - Ensure that power valve actuator rod moves when changing the gear position to "N" and "D" alternately. See Figure. If results are as specified, inspection is complete. If results are not as specified, go to step  3.
  2. Stop engine and disconnect vacuum hose connected to power valve actuator. Start engine and let it idle. Using CONSULT-II, perform VIAS SOL VALVE in ACTIVE TEST mode with CONSULT-II. Turn VIAS control solenoid valve ON and OFF, and check vacuum existence. If VIAS SOL VALVE is ON, vacuum should exist. If VIAS SOL VALVE is OFF, vacuum should not exist. If results are as not specified, repair or replace power valve actuator. If results are as specified, go to step  4.
  3. Stop engine and disconnect vacuum hose connected to power valve actuator. Start engine and let it idle. Apply 12 volts between VIAS control solenoid valve terminals No. 1 and 2. See Figure. Check vacuum existence under the following conditions. If 12 volts is applied, vacuum should exist. If voltage is not applied, vacuum should not exist. If results are not as specified, repair or replace power valve actuator. If results are as specified, go to next step.
  4. Stop engine, check hoses and tubes between intake manifold and power valve actuator for cracks, clogging, improper connection or disconnection. If no problem is found, go to next step. If problem is found, repair as necessary.
  5. Check vacuum tank. Repair or replace as necessary. Go to next step.
  6. Turn ignition switch to OFF position. Disconnect VIAS control solenoid valve harness connector. Turn ignition switch to ON position. Check voltage between terminal No. 1 and ground. Battery voltage should exist. See Figure. If voltage is as specified, go to step  8. If voltage is not as specified, go to next step.
  7. Check the following:
    • Harness connectors E211 and M41.
    • Harness connectors M82 and F102.
    • IPDM E/R connector E7.
    • 10-amp fuse.
    • Harness continuity between IPDM E/R and VIAS control solenoid valve.

    Repair harness or connectors as necessary.

  8. Turn ignition switch to OFF position. Disconnect ECM harness connector. Check harness continuity between ECM terminal No. 29 and terminal No. 2. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL. Continuity should exist. Check harness for short to ground and short to power. If no problem is found, go to next step. If problem is found, repair harness or connectors as necessary.
  9. Check VIAS control solenoid valve. If results are as specified, go to next step. If results are not as specified, replace VIAS control solenoid valve.
    • With CONSULT-II  - Reconnect disconnected harness connectors. Turn ignition switch to ON position. Perform VIAS SOL VALVE in ACTIVE TEST mode. Check air passage continuity and operation delay time.

      If VIAS SOL VALVE is ON, air passage continuity between "A" and "B" should exist, and air passage continuity between "A" and "C" should not exist. See Figure. If VIAS SOL VALVE is OFF, air passage continuity between "A" and "B" should not exist, and air passage continuity between "A" and "C" should exist.

    • With GST  - Check air passage continuity and operation delay time under the following conditions. If 12 volts is applied between terminals No. 1 and 2, air passage continuity between "A" and "B" should exist, and air passage continuity between "A" and "C" should not exist. See Figure. If no voltage is applied, there will be no air passage continuity between "A" and "B", but there will be air passage continuity between "A" and "C".
  10. No problem is indicated at this time. Problem may be intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article.
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