Circuit Description

PCM uses an Electrically Erasable Programmable Read Only Memory (EEPROM). EEPROM contains program information and calibrations required for engine, transaxle, and powertrain diagnostics operation. If PCM detects an internal program fault (check sum error), DTC P0601 will set.

When DTC sets, PCM illuminates MIL as soon as fault was detected. PCM will store conditions present when DTC was set as FREEZE FRAME data in the FAILURE RECORDS data. A history DTC is set.

PCM will turn MIL off on third consecutive trip cycle during which diagnostic runs and fault is no longer recognized. A history DTC will clear after 40 consecutive ignition cycle which diagnostic runs and fault is no longer recognized. DTC can be cleared with scan tool, or by disconnecting battery voltage feed to PCM.