Diagnostic Aids
WARNING: This page is about a different car, the 2002 Isuzu Trooper. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0601 indicates that contents of EEPROM have changed since PCM was programmed. Only repair is PCM replacement. Ensure replacement PCM is reprogrammed using correct software and calibration for vehicle. See EEPROM PROGRAMMING PROCEDURE under POWERTRAIN CONTROL MODULE.