Code P112, EEPROM Failure

Electrically Erasable Programmable Read Only Memory (EEPROM) is used by PCM to store data even when battery power is removed. It stores TP sensor/idle learned values, transaxle adapt values, transaxle oil life index and cruise control lash/learn. EEPROM store this information in several locations and if PCM detects a problem in one location of EEPROM, it will store data in another location. If PCM runs out of good locations in the EEPROM to store data, Code P112 will be stored.

PCM stores the same data in its Keep Alive Memory so that even if EEPROM is bad, Code P112 will set. Vehicle operation will remain unchanged. Even after a code is set, PCM will continue to look for good locations in the EEPROM to store data. If a good location is found, Code P112 will become a history code. If Code P112 is present, PCM must be replaced.

1. If Code P112 is set current, PCM cannot find another location to store data. Replace PCM.
2. Cycle ignition to PCM a chance to find a place to store data. If trouble code resets, PCM must be replaced.

Fig 1: Code P112 Schematic, EEPROM Failure

Courtesy of GENERAL MOTORS CORP.