Cautions When Servicing PCM

CAUTION: The Powertrain Control Module (PCM) on this vehicle should not be removed without reviewing service procedures of the PCM and EEPROM. Replacement and/or removal of the PCM may cause the EEPROM memory to reset and the vehicle to have a no start or poor running condition. Replacement of the Instrument Panel Cluster may also cause the EEPROM to reset. CHECK WITH A DEALER BEFORE PERFORMING PCM REPLACEMENT.

The PCM on this vehicle is equipped with an EEPROM that is designed to lose memory under certain conditions. The EEPROM is not serviceable and should not be removed for replacement. If the PCM is removed from the vehicle, reprogramming of the EEPROM will be necessary. Reprogramming of the EEPROM is only possible with hardware available at authorized dealers. Check with a dealer before performing PCM replacement. If you do not have the equipment to reprogram the PCM after replacement, DO NOT attempt replacement.

PURPOSE
The PCM contains a data storage unit which can save critical data even when battery power is removed. This unit, the Electronically Eraseable Programable Read Only Memory (EEPROM) is used by the PCM to store sensor learned values, oil life indexes and odometer value. The PCM EEPROM also stores vehicle information such as engine and transaxle calibrations, Vehicle Identification Number, programmable vehicle option content and Malfunction history. Some values are stored in the EEPROM during the first 30 seconds after the key is turned "OFF".

Vehicle information stored on the PCM EEPROM has a major effect on how the vehicle will operate.


OPERATION
The EEPROM is soldered in the PCM and cannot be serviced separately. During PCM replacement, the EEPROM looks at the Instrument Panel Cluster's reading of the odometer and compares it with the odometer reading previously stored in the PCM EEPROM. If the value is different, the EEPROM will reset and learn new values.

LOCATION
The EEPROM is located inside the PCM and is not removeable or serviceable.



DEFINITION
The term EEPROM Reprogramming means to electronically change the contents of the Electronically Erasable Programmable Read Only Memory (EEPROM) in the PCM.

REPROGRAMMING THE EEPROM
Reprogramming of PCM EEPROM information is necessary when replacing a PCM, or when changing the engine and/or transaxle calibrations. It is essential that a replacement PCM be reprogrammed with the correct VIN. option content, tire size, and calibration information. Reprogramming of the EEPROM may only be possible with hardware available at authorized dealers. Check with a dealer before performing PCM replacement. If you do not have the equipment to reprogram the PCM after replacement, DO NOT attempt replacement.