35 Idle Air Control (IAC) - RPM Out of Range

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The idle air control (IAC) consists of a two coil stepper motor controlling a valve. The motor is used to move the IAC valve pintle in and out of a seat to control the amount of air that enters the intake manifold at idle.

Code Parameters

Code 35 will set if:

  • Idle speed is greater than desired after PCM commanding the IAC motor closed.
  • Idle speed is less than desired after PCM commanding the IAC motor wide open.

Diagnostic Aids

  • When attempting to diagnose an intermittent problem use the Scan Tool to review supplemental diagnostic information. The supplemental data can be used to duplicate a problem. Select MALF History from Scan Tool EC menu.
  • Check the tightness of the female terminal grip with a spare male terminal.
  • Desired idle is based on a look-up table or anything that requires an idle speed boost will effect desired idle.
  • The desired idle speed can be found in either the Scan Tool or the SATURN Service stall system.
  • IAC is controlled by the PCM with four pulse width modulated (PWM) outputs.
  • Cruise cable misadjustment may cause a high idle due to throttle plates being held open.
  • Inspect PCV valve and system.