Idle Learn: Description

An idle problem may exist when the ECM loses track of the true position of the IAC pintle. The IAC counts read on the scan tool only reflect the commands sent out by the ECM. If ECM counts begin at the wrong starting point, the counts will be off and the idle speed will be wrong. The ECM loses track of the IAC when the IAC is disconnected with the ignition ON (engine off or running) or when battery power to the ECM has been interrupted for any reason.

To get the ECM and IAC working together again, the ECM has to reset the IAC valve and "learn" where to place the pintle to obtain the correct idle.