Powertrain Control Module

WARNING: This page is about a different car, the 2003 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The following information/procedure is as per Service Bulletin No. 02-09-04-001-(05/24/2002): DTCs B1001, B1271 or B1780 SET WHEN REPLACING/REPROGRAMMING OTHER MODULES.

Class 2 Serial Data Communication allows control modules to exchange information. This information may be operational information or identification information. Among the identification information exchanged and compared within these modules is the Vehicle Identification Number (VIN). Typically the one module, the master module, broadcasts the VIN and all the other modules compare the VIN stored within itself. When the broadcast VIN does not match the VIN stored within the Sensing and Diagnostic Control Module (SDM), the following actions occur:

DTC B1001 Option Configuration Error is set and deployment of the air bags is inhibited.
DTC B1271 or a DTC B1780 Theft Locked. The VIN information is also used by the radio. When the VIN does not match the VIN stored within the radio, DTC B1271 or DTC B1780 is set and the radio is inoperative.

Additionally, the master module will compare the SDM's part number (last 4 digits) to determine if the correct SDM is installed in the vehicle. If the SDM is the wrong part, DTC B1001 will also set.

When a PCM or a body control type module is replaced, the VIN information must be programmed into the replaced (NEW) control module. A module which has had VIN information entered into it (for example, one taken from another vehicle) cannot be reprogrammed. VIN information can only be entered into new modules. The ignition switch must be in the RUN position to program the NEW control module. Since the VIN information is broadcast when the ignition goes to RUN position from any other ignition switch position, DTCs may be set in the SDM and/or the radio. Therefore, always follow the specified control module replacement procedures:

After completing the repair, turn ignition switch to OFF position for at least 30 seconds.
Turn ignition switch to RUN position and check for DTCs using a Tech 2(R) scan tool, or equivalent. If DTCs B1001, B1271, or B1780 are present with a history status, DO NOT replace the SDM or the radio.
Clear DTCs from all modules using the scan tool.
Remove scan tool.
Ensure proper operation of the SDM by turning the ignition switch to OFF position and then to RUN position. The air bag warning indicator should flash 7 times and then go OFF.

Clearing codes from the other modules is part of the replacement and reprogramming procedure for the replaced module. The repair is not complete unless all codes have been cleared from all modules.