B3135

DTC B3125, B3130, or B3135

Diagnostic Instructions

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

DTC Descriptors
DTC B3125 02
- Driver Door Only Unlock Circuit Short to Ground

DTC B3125 04
- Driver Door Only Unlock Circuit Open

DTC B3130 02
- All Doors Unlock Circuit Short to Ground

DTC B3130 04
- All Doors Unlock Circuit Open

DTC B3135 02
- All Doors Lock Circuit Short to Ground

DTC B3135 04
- All Doors Lock Circuit Open

Diagnostic Fault Information





Circuit/System Description

The body control module (BCM) controls the door lock, passenger door unlock and driver door unlock circuits. Voltage is applied to the appropriate circuit when the BCM senses a door lock/unlock switch activation or a keyless entry lock or unlock command.

Conditions for Running the DTC

The system voltage is 9-16 V.

Conditions for Setting the DTC

B3125 02, B3130 02, B3135 02

The BCM detects a short to ground on a door latch control circuit.

B3125 04, B3130 04, B3135 04

The BCM detects an open/high resistance on a door latch control circuit

Action Taken When the DTC Sets

All the power door locks will be inoperative.

Conditions for Clearing the DTC

* This DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Reference Information
Schematic Reference

Door Lock/Indicator Schematics (Door Lock/Indicator Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Power Door Locks Description and Operation (Description and Operation)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

Command the door latches to LOCK and UNLOCK with a scan tool. Observe the operation of the door latches, each door should LOCK and UNLOCK when changing between the commanded states.

If one or more doors do not LOCK or UNLOCK, refer to Door Lock Malfunction.
If all the door latches are inoperative, refer to All Door Locks Inoperative.

Circuit/System Testing

Door Lock Malfunction
1. Ignition OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Connect a test lamp between the control circuit terminals listed below:

* A23D door latch assembly-driver terminal 2 and terminal 3
* A23P door latch assembly-passenger terminal 7 and terminal 8
* A23LR door latch assembly-left rear terminal 2 and terminal 3
* A23RR door latch assembly-right rear terminal 7 and terminal 8

3. Ignition ON, command the door to LOCK and UNLOCK by using the central door lock switch. The test lamp should briefly illuminate when commanding the LOCK and UNLOCK states.

• If the test lamp is always OFF for either the LOCK or UNLOCK command, test the control circuit for an open/high resistance between the connector and the circuit splice.

4. If all circuits test normal, test or replace the A23 door latch assembly.

All Door Locks Inoperative
1. Ignition OFF, disconnect the X2 harness connector at the K9 BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 4 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X2 harness connector and disconnect the X6 harness connector at the K9 BCM.
4. Test for infinite resistance between the control circuit listed below and ground:

* Control circuit terminal 1
* Control circuit terminal 2
* Control circuit terminal 4

• If not the specified value, test the appropriate control circuit for a short to ground. If the circuit tests normal, test or replace the appropriate A23 door latch assembly.

5. If all circuits test normal, replace the K9 BCM.

Component Testing

1. Ignition OFF, disconnect the harness connector at the appropriate A23 door latch assembly.
2. Install a 25 A fused jumper wire between one of the control terminals and 12 V. Momentarily install a jumper wire between the other control terminal and ground. Reverse the jumper wires at least two times, the A23 door latch assembly should perform the LOCK and UNLOCK functions.

• If it does not perform as specified, replace the A23 door latch assembly.

Repair Instructions

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

* Front Side Door Lock Replacement (Front Side Door Lock Replacement)
* Rear Side Door Lock Replacement (Rear Side Door Lock Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming