Idle Speed
Idle speed is controlled by ECU through AAC valve. ECU controls idle speed component(s) based upon signals received from various input devices. If idle speed component(s) test correctly but idle speed is not being regulated properly, check the following input signals to ECU:
- A/C Clutch Signal - Signal received from automatic A/C amplifier.
- Airflow Meter.
- Battery Voltage.
- Crank Angle Sensor.
- Engine (Coolant) Temperature.
- Ignition (START) Switch.
- Park/Neutral (Inhibitor) Switch - Signal received from P/N relay.
- Power Steering Pressure Switch.
- Throttle Position Sensor.
- Throttle (Idle) Switch.
- Vehicle Speed Sensor.