Idle Control System: Notes
WARNING: This page is about a different car, the 1998 Infiniti Q45 and 1998 Infiniti I30. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Fast idle is actuated by fast idle cam. For fast idle cam adjustment procedure, see IDLE SPEED & MIXTURE in ADJUSTMENTS
article.
Idle speed is controlled by PCM through IAC valve. PCM controls idle speed components based upon signals received from various input devices. If idle speed components test correctly but idle speed is not being regulated properly, check the following input signals to PCM.
- A/C Operation
- Closed Throttle Position Switch
- Crankshaft Position Sensor
- Engine Coolant Temperature
- Ignition (Start) Signal
- Mass Airflow Sensor
- Park/Neutral Switch
- Power Steering Pressure Switch
- Throttle Position Sensor
- Vehicle Speed Sensor