GM Service Manual Online
For 1990-2009 cars only

Important: DO NOT replace the Body Control Module (BCM) unless a Diagnostic Trouble Code (DTC) remains current after all of the DTC tables are executed. DO NOT replace the BCM based on the history codes.

The BCM is connected to the Class 2 serial data link. The BCM is capable of setting the DTCs. A history DTC is a fault that disappears in the next ignition cycle. The history DTCs may be especially useful in diagnosing an intermittent problem. An explanation of the history DTCs are given below in the DTC table.

DTC Table

Diagnostic Trouble Code

Explanation

Passlock™ Theft Deterrent

B2947

Passlock™ power output short to ground

B2948

Passlock™ power output short to battery

B2957

Passlock™ signal data shorted to ground

B2958

Passlock™ signal data open/short to battery

B2960

Passlock™ cylinder data incorrect

B3031

Body Control Module (BCM) in learn mode (current code only)

B3033

Passlock™ signal data indicates tamper