Idle Speed/Throttle Actuator - Electronic: Description and Operation

ENGINE CONTROL COMPONENTS

Cold Idle Kicker
The cold idle kicker strategy provides an increase in idle speed during cold engine warm up. During extended idle conditions, the PCM increases engine speed up to 1,100 RPM (normally 725 RPM for manual, 690 RPM for auto) to achieve a faster engine warm-up. The PCM uses the engine oil temperature (EOT) sensor and intake air temperature 2 (IAT2) inputs and adjusts the RPM accordingly, to a maximum of 1,100 RPM.

The idle speed is increased proportionately when the engine oil temperature is less than 70°C (158°F), the IAT2 is less than 20°C (68°F) and the engine has been at idle for more than 2 minutes. Applying the brake pedal, accelerator pedal, parking brake or clutch pedal (manual transmission) deactivates the cold idle kicker strategy and returns the idle speed to 690 RPM.

Allowing the engine to idle for more than 5 minutes with the EGR valve commanded closed, the variable geometry turbocharger duty cycle may step from 15% to 85%. This occurs momentary and repeats after a calibrated time. For additional information, refer to Powertrain Control Software, Vane Sweep. Powertrain Control Software