GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2007 🢒 Lumina VE 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B3125

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category

DTC Descriptor

DTC B3125 00: All Door Lock Circuit

Circuit/System Description

When the door lock switch is placed in to the LOCK position, ground is applied through the switch to the body control module (BCM). The BCM then applies a voltage through the door lock relay control circuit to the coil side of the lock relay in the X129 IP Fuse Centre. The relay then engages and applies voltage to all the door lock assemblies.

Conditions for Running the DTC

The ignition is ON.

Conditions for Setting the DTC

The BCM receives a ground signal on the door lock relay control circuit

Action Taken When the DTC Sets

The BCM ceases all attempts to lock the doors.

Conditions for Clearing the DTC

The BCM clears this code from current when the fault is removed from the system.

Reference Information

Schematic Reference

Door Lock/Indicator Schematics .

Connector End View Reference

Component Connector End Views

Electrical Information Reference

    •  Circuit Testing .
    •  Connector Repairs .
    •  Testing for Intermittent Conditions and Poor Connections .
    •  Wiring Repairs .

Scan Tool Reference

Control Module References

Circuit/System Verification

Ignition ON, place the door lock switch to the LOCK position. All doors should lock.

Circuit/System Testing
  1. Disconnect the R2 lock relay in the X129 IP fuse centre. Verify the DTC resets.
    2. ⇒If the DTC does not reset, replace the relay.
  2. Disconnect the IP fuse centre connector P220. Verify the DTC resets.
    3. ⇒If the DTC does not reset, replace the IP fuse centre.
  3. Test for a short to ground in the door lock relay control circuit.
    4. ⇒If all circuits/connections test normal, replace the BCM.

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for BCM replacement, setup, and programming
    •  Underhood Electrical Center or Junction Block Replacement in Wiring Systems.