DTC B3127: Driver's Door Unlock Circuit (Short To Ground Or Open): Description

WARNING: This page is about a different car, the 1999 Buick Regal and 1999 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

When Body Control Module (BCM) receives driver door unlock request from door lock switches or keyless entry transmitter, it supplies ground through circuit No. 1391 (Light Green wire) to energize door lock relay.

DTC B3127 will set when BCM detects a short to ground or open in circuit No. 1391 (Light Green wire). No driver warning message will be displayed.

If conditions for malfunction no longer exist, history DTC will clear after 100 consecutive ignition cycles. DTC B3127 will also clear when conditions no longer exist or scan tool is used to clear codes.

NOTE: If DTC B3127 is a history code, problem may be intermittent. Wiggle wires while performing the following test.

NOTE: When ignition switch is turned to RUN position with BCM disconnected, PCM-related DTC P1626 will be set. After BCM repair is completed, see appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.