PCM - Reprogramming

BULLETIN NUMBER:
IBOO-S002

ISSUE DATE:
JANUARY 2000

GROUP:
INFORMATION

PCM REPROGRAMMING

AFFECTED VEHICLES

All Isuzu built units with reprogrammable PCM.

It is strongly recommended NOT to reinstall the same software or calibration files when reprogramming a Powertrain Control Module. There is no technical reason that the download files inside the PCM would ever become corrupted after the control module had previously been successfully programmed. With the 2.2L and 4.3L Hombre, a P0601 (Control Module Read Only Memory) Diagnostic Trouble Code could set in memory and the MIL could illuminate if the controller memory became corrupted.

After a necessary reprogramming, it is feasible that certain learned values such as fuel trim, IAC learned positions, certain OBD II diagnostic thresholds, and automatic transmission shift adapts for the engine or transmission might revert back to their original unlearned starting points. As a result, the engine and transmission may temporarily operate differently until the values are re-learned.