Check Engine Light On Dash
Check Engine Light On, Sensor Descriptions

Idle Air Control

Choose the sensor below for descriptions
  1. Powertrain Control Module (PCM)
  2. Throttle Position (TP) sensor
  3. Mass Air Flow (MAF) sensor
  4. Intake Air Temperature (IAT) sensor
  5. Idle Air Control (IAC) valve
  6. Engine Coolant Temperature (ECT) sensor
  7. Heated Oxygen Sensor (HO2S)
  8. Camshaft Position (CMP) sensor
  9. Knock Sensor (KS)
  10. Vehicle Speed Sensor (VSS)
  11. Crankshaft Position (CKP) sensor
  12. Fuel Injector
  13. Coolant Temperature Sensor (CTS)
  14. Exhaust Gas Recirculation (EGR)
  15. Manifold Absolute Pressure (MAP)


Idle Air Control (IAC)

The Idle Air Control (IAC) valve controls the engine idle speed and dashpot functions. The valve is located on the side of the throttle body. This valve allows the necessary amount of air, as determined by the Powertrain Control Module (PCM) and controlled by a duty cycle signal, to bypass the throttle plate in order to maintain the proper idle speed.

IAC Valve

Idle speed control is accomplished through the use of the Idle Air Control (IAC) motor or IAC valve in combination with ignition timing. Some applications use a second air passage and control device to provide additional air to compensate for the additional load created when the A/C compressor is running. The pintle-type IAC motor typically has a dual winding driven pintle that controls the size of a metered orifice that is part of the throttle body housing. The pintle seat will be at or near the axis of the throttle plate(s).

IAC Valve