Once the locks are free you simply pull the connectors out. Here is how the PCM is replaced in the instructions below with diagrams showing the PCM location and replacement procedure.
The ECM has a learning ability that allows it to adjust the fuel control system to compensate for a rich or lean engine running condition. The ECM uses long term fuel trim cells, which are averages of the short term fuel trim cells. The short term fuel trim cells continuously adjust the amount of fuel the engine needs based on signals from the pre-catalyst oxygen sensors. If DTCs are cleared, the battery is disconnected, or if the ECM is replaced, the ECM long term fuel trim cells are reset to 0% and the ECM will adjust for variations in the fuel once the pre-catalyst oxygen sensors are functioning. If the engine was running rich or lean before the long term fuel trim cells were cleared, a notice in driveability may result until the ECM updates the long term fuel trim cells. The vehicle should be brought up to normal operating temperature of 80°C (176°F) to allow the ECM to adjust for any rich/lean engine running condition.
The ECM also has the ability to learn the throttle body, which allows it to learn the 0% and rest (7%) TP sensor position values as well as ensure both return spring rates within the throttle body are within acceptable limits. The ECM will automatically relearn the throttle body if the ignition is turned On for longer than 29 seconds with the ECT and IAT above a certain range (see Minimum Throttle Position Not Learned DTC). The ECM will automatically relearn the throttle body upon key-up if the battery is disconnected or the ECM has been replaced or reprogrammed. The throttle body should always be relearned if a new throttle body or ECM has been replaced. To relearn, key-up for 1 minute with the ignition On, engine Off while keeping foot Off accelerator pedal.
The ECM also has the ability to learn the crankshaft notch variation used to correctly detect engine misfires. The ECM continuously and automatically under all speed and load ranges learns the notch variation. It is important to reset the CKP notch variation adaptives using the Scan tool ONLY when a crankshaft is replaced. If the ECM is replaced or reprogrammed, the adaptives will be reset and the threshold to set misfires will be relaxed.
Check out the diagrams (Below). Please let us know what you find.
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Tuesday, October 20th, 2020 AT 4:51 PM
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