Circuit Description

The Idle Air Control (IAC) valve is controlled by the Powertrain Control Module (PCM). PCM uses the IAC to maintain a desired idle speed, which can vary depending on input to PCM. Scan tool reads IAC valve pintle position in counts. The higher the counts, the more air that is allowed to by-pass the throttle plate.

Conditions for setting this DTC are as follows:

• IAC valve counts are greater than 145.
• BARO is greater than 72 kPa.
• TP angle is less than one percent.
• Engine coolant temperature is greater than 104°F (40°C).
• Battery output is 10-17 volts.
• No presence of Codes: P0106-P0108, P0112, P0113, P0117, P0118, P0121-P0123, P0125, P0131-P0134, P0335, P0341, P0342, P0502, P0503, P0562, P0563, P0600, P1133, P1520.
• Engine run time is greater than 20 seconds.
• Idle speed is greater than 60 RPM less than desired RPM for more than 5 seconds.