B3130

DTC B3130

Diagnostic Instructions

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

DTC Descriptor
DTC B3130 00
- All Door Unlock Circuit

Diagnostic Fault Information






Circuit/System Description

The rear passenger door locks are controlled by the body control module (BCM). When a door lock switch is operated to the lock position, the BCM applies voltage to the rear door lock actuator lock control circuit which energizes the lock relay. With the lock relay coil energized, the switch contacts close allowing battery voltage to flow from the DOOR LKS fuse through the relay switch contacts to the left and right door lock/unlock motors. A ground path is provided by the unlock relay controlled output circuit through the unlock relay switch contacts to ground. The process to unlock the rear doors reverses the flow of current. The BCM applies ground to the rear door lock actuator unlock control circuit which energizes the unlock relay coil. With the unlock relay coil energized, the switch contacts close allowing battery voltage to flow from the DOOR LKS fuse through the relay switch contacts to the left and right door lock/unlock motors. Ground is provided through the lock relay controlled output circuit through the lock relay switch contacts to ground.

Conditions for Running the DTC

Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

DTC B3130 00 will set when the BCM detects a short to voltage in the rear door unlock control circuit.

Actions Taken When the DTC Sets

The BCM will disable all rear door unlock requests.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* You issue a scan tool CLEAR DTCs command.
* A history DTC will clear once 50 consecutive malfunction-free ignition cycles have occurred.

Circuit/System Testing

1. Ignition OFF, disconnect the unlock relay.
2. Connect a test lamp between the B+ circuit terminal R35 and the control circuit terminal R31.
3. Command the rear door locks to LOCK and UNLOCK with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

4. If the circuits test normal, test or replace the unlock relay.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Relay Replacement (Within an Electrical Center)
* Control Module References for BCM replacement, setup, and programming. Programming and Relearning