Electrical Load Idle-Up Signals

The Powertrain Control Module (PCM) receives signals from several electrical components when any of the following electrical loads are present:
^ Rear window defogger
^ Headlights

The PCM will increase the engine idle speed when receiving an electrical load input. The PCM will signal the Idle Air Control (IAC) valve to open the idle air passage. Opening the idle air passage slightly will maintain an engine speed that provides a desirable idle. The PCM will return the engine to the original idle when the electrical load signal is removed.