The Electronic Control Module, or ECU as it is most commonly called, is a generic term used for any embedded system within a vehicle that controls one or more electric system(s) or subsystem(s). The following sequence is used to reset the ECM or PCM as it is sometimes refered too.
1. Disconnect the battery by removing the Negative battery cable (This will ensure that any possibility of grounding the power side to the vehicle [or yourself - think wedding ring] does not happen.)
2. Disconnect the Positive battery cable
3. Allow a few moments to pass before reconnecting the cables
4. Reconnect the positive cable to the battery
5. Reconnect the negative cable to the battery
6. Turn the Vehicle on
2. Disconnect the Positive battery cable
3. Allow a few moments to pass before reconnecting the cables
4. Reconnect the positive cable to the battery
5. Reconnect the negative cable to the battery
6. Turn the Vehicle on
The ECM parameters for all sensor calibration monitors have now been reset. It can take anywhere from a few minutes to a few days for all of the system parameters to be restored within the unit.