Powertrain Controls - ECM/PCM

NOTE: This article refers to the recalibration procedure of the EEPROM with the GM Tech 1 scanner or CAMS machine. Refer to your scanner for reprogramming procedures, if available.

Powertrain Control Module (PCM) calibrations are stored in the Electronically Erasable Programmable Memory (EEPROM). The EEPROM is not removable from the PCM. DTC 51 will set if no calibration was programmed in the PCM, or when the PCM detects an internal program fault (checksum error). If DTC 51 sets during normal vehicle operation, replace the PCM. The replacement PCM must be programmed using the Tech 1 (T1) or CAMS (T100).

Use the following procedure to reprogram the PCM:

CAUTION: The software/calibration used for PCM reprogramming must match the vehicle application, or improper operation and/or vehicle damage may occur.

^ Battery is charged.
^ Ignition is "ON".
^ Connections to the DLC and Battery/Cigar Lighter secure (Tech 1 hookups).
^ Follow the most current Techline terminal/Equipment instructions.

If the PCM fails to program, or if DTC 51 sets during programming:
^ Check all PCM connections.
^ Check Techline terminal/Equipment for latest software version.
^ Repeat reprogramming procedure. If it fails again, replace the PCM. The replacement PCM must be programmed.