GM Service Manual Online
For 1990-2009 cars only

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 B3135 00: All Door Lock Circuit

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Door Lock Relay Control

B3135 00

1

1

--

1. Power Door Locks Inoperative - All Doors

Circuit/System Description

When the door lock switch is place 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 body electrical center (BEC). 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 cease attempt 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

    •  Scan Tool Output Controls
    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Circuit/System Verification

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

Circuit/System Testing

  1. Disconnect the Lock relay in the BEC. Verify the DTC resets.
  2. If the DTC does not reset, replace the Relay.
  3. Disconnect the BEC connector C1. Verify the DTC resets.
  4. If the DTC does not reset, replace the BEC.
  5. Test for a short to ground in the door lock relay control circuit.
  6. If all circuits/connections test normal, replace the BCM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    • Instrument Panel Electrical Center or Junction Block Replacement - Right Side
    •  Relay Replacement
    •  Control Module References for BCM replacement, setup, and programming