GM Service Manual Online
For 1990-2009 cars only

All Door Unlock Circuit Low


Object Number: 864379  Size: MF

Circuit Description

The door locking/unlocking, by remote keyless entry (RKE) or driver/passenger door lock switches, is controlled through the body control module (BCM).

When an all doors unlock has been requested, the BCM switches circuit 194, to battery voltage. This energizes the other door lock relay which supplies power to all passenger door lock motors. Grounding is achieved through the closed contacts of the unlock relay.

The lock/unlock power application is limited by the BCM to 0.375 seconds to protect the lock motors.

Conditions for Setting the DTC

    • All door unlock is requested.
    • Circuit 194 is shorted to ground.

Diagnostic Aids

    • When a shorted-to-ground condition exists in circuit 194 and the BCM has been requested to activate the door lock relay, the BCM will attempt to switch circuit 194 to battery voltage. High current flow will result and the BCM output will go into a protective state. The BCM output will not allow itself to be activated for as much as 3 minutes.
    • Inspect the wiring harness for damage. Check for broken or chafed insulation.
    • If a fault is suspected to be intermittent, wiggling the harness wiring may help in locating the fault.

Object Number: 874671  Size: FP