How to Do an Idle Relearn
In the event you are experiencing an erratic idle after loading a tune or after performing any action that clears KAM (Keep Alive Memory), an Idle Relearn can help you get back on track.
The KAM or “Keep Alive Memory” is the memory that is stored in the powertrain control module (PCM). This memory contains data regarding idle trims, fueling adjustments, adaptive shifting, and many other parameters. It is constantly updated as the vehicle is driven to account for changes in environment, driving conditions, and even wear on the vehicle.
The KAM is cleared anytime battery power is disconnected from the PCM. Examples would be: disconnecting the battery, replacing battery or battery cables, a dead battery, or a bad ground. Also, many SCT devices contain a “Clear KAM” command in the “Special Functions” menu of the device that will also clear KAM, without the need to disconnect the battery.
When KAM is cleared, or battery power is lost, the computer returns to the base parameters set in the calibration, and loses the stored values it has gathered based on driving habits, inputs, and data collected by the vehicle sensors. When this happens it is sometimes necessary to perform an idle relearn to once again teach the car how to idle correctly.Follow these steps to complete an Idle Relearn:
- With vehicle at a complete stop, set the parking brake.
- Put gear shifter in "P" (Park), turn off all accessories.
- Run the engine until it reaches normal operating temperature.
- Allow engine to idle for at least one minute.
- Turn the air conditioning on and allow the engine to idle for at least one minute.
- Release the parking brake. With your foot on the brake pedal and the A/C still on, put the vehicle in "D" (Drive) and allow the engine to idle for at least one minute.
- Drive the vehicle to complete the relearning process. Just make sure you drive easy for the first 30 miles, so the PCM can re-learn and adapt to your driving style.