1998 Infiniti QX4FACTORY OEM SERVICE PROCEDURE

Fast Idle Control Device (FICD) System Test: Altima

  1. Start engine and warm to operating temperature. Check idle speed. See SPECIFICATIONS article. Adjust idle speed if necessary. See ADJUSTMENTS article. Turn A/C switch and blower fan switch on. Idle speed should increase. If idle speed does not increase, go to next step. If idle speed increases, system is functioning properly.
  2. Ensure A/C compressor functions normally. If compressor is not functioning, repair A/C system as necessary. If compressor is functioning, go to next step.
  3. Turn ignition off. Disconnect FICD solenoid harness connector. Start engine. Using DVOM, measure voltage between ground and FICD harness connector terminal No. 1 (Yellow/Black wire). Battery voltage should be present. If battery voltage is present, go to next step. If battery voltage is not present, check and repair open or short in Yellow/Black wire. If wire is okay, check fuse, A/C relay, and FICD solenoid. Repair or replace as necessary.
  4. Check ambient air temperature switch. See A/C-HEATER SYSTEMS article in the AIR CONDITIONING & HEAT section. If ambient air temperature switch is okay, go to next step. If ambient air temperature switch is not okay, replace as necessary. Retest system.
  5. Ensure engine is still at operating temperature. Turn ignition off. Check continuity between ground and FICD solenoid harness connector terminal No. 2 (Black wire). Continuity should exist. If continuity exists, go to next step. If continuity does not exist, repair open in Black wire.
  6. Check FICD solenoid. See FAST IDLE CONTROL DEVICE (FICD) SOLENOID . If FICD solenoid is okay, check PCM terminals and harness connector terminals for pushed-out, damaged, or corroded terminals. Repair or replace as necessary.
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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

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