B3125
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 00
- Left Front/Driver Door Only Unlock Circuit
DTC B3130 00
- All Door Unlock Circuit
DTC B3135 00
- All Door Lock Circuit
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM), upon receipt of a lock switch lock signal, will switch the door lock relay control circuit to battery positive voltage. This will energize the LOCK relay. The remaining unlock relays receive voltage from the underhood fuse block, the BCM upon receipt of a unlock signal or driver door unlock signal will switch the appropriate unlock relay to ground. This will energize the appropriate unlock relay unlocking the appropriate doors.
Conditions for Running the DTC
The system voltage must be between 9-16 V.
Conditions for Setting the DTC
B3125 00
The BCM detects a short to voltage or an open/high resistance in the driver door unlock control circuit.
B3130 00
The BCM detects a short to voltage or an open/high resistance in the door unlock control circuit.
B3135 00
The BCM detects a short to ground in the door lock control circuit.
Action Taken When the DTC Sets
The power door locks will malfunction.
Conditions for Clearing the DTC
* The 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 1-2 Shift Solenoid (SS) Valve (MN5)
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 by using the door lock switch-driver, all doors should LOCK and UNLOCK when changing between the commanded states.
Circuit/System Testing
All Door Locks inoperative
1. Ignition OFF, disconnect the X2 harness connector at the X51A fuse block-instrument panel.
2. Connect a test lamp between the control circuit terminal 11 and ground.
3. Ignition ON, command the doors to LOCK with a scan tool. The test lamp should illuminate during the LOCK command.
• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 body control module
• If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K9 body control module
4. Connect a test lamp between the control circuit terminal 10 and B+.
5. Command the doors to UNLOCK with a scan tool. The test lamp should illuminate during the UNLOCK command.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 body control module.
• If the test lamp is always OFF, test the control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the K9 body control module.
6. Connect a test lamp between the control circuit terminal 12 and B+.
7. Command the driver door to UNLOCK with a scan tool. The test lamp should illuminate during the UNLOCK command.
• If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the K9 body control module.
• If the test lamp is always OFF, test the control circuit for a short to voltage or and open/high resistance. If the circuit tests normal, replace the K9 body control module.
8. If all circuits test normal, replace the X51A fuse block-instrument panel.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Instrument Panel Wiring Harness Junction Block Replacement Instrument Panel Wiring Harness Junction Block Replacement
* Control Module References Programming and Relearning for BCM replacement, programming and setup