B3125

DTC B3125, B3130, or B3135

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 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) controls the door lock, passenger door unlock and driver door unlock relays. Voltage is applied to the appropriate relay through the door lock/unlock control 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 9-18 volts.

Conditions for Setting the DTC

B3125 00

The BCM detects a fault in the driver door unlock control circuit while commanding the DRV UNLCK relay.

B3130 00

The BCM detects a fault in the door unlock control circuit while commanding the PASS UNLCK relay.

B3135 00

The BCM detects a fault in the door lock control circuit while commanding the DR/LCKS relay.

Action Taken When the DTC Sets

* The BCM stores the DTC to memory.
* The power door locks will not operate.

Conditions for Clearing the DTC

* This DTC will change from current to history when the fault is no longer present.
* A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

Circuit/System Verification

Command the driver door and passenger door lock actuators to LOCK and UNLOCK with the scan tool, the doors should LOCK and UNLOCK.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the body fuse block.
2. Connect a test lamp between the control circuit terminal 5 and ground.
3. Ignition ON, command the lock rear doors ON and OFF 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 voltage. If the circuit tests normal, replace the BCM.
• 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 BCM.

4. Connect a test lamp between the control circuit terminal 18 and B+.
5. Command the driver door unlock ON and OFF 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 and open/high resistance. If the circuit tests normal, replace the BCM.

6. Connect a test lamp between the control circuit terminal 11 and B+.
7. Command the unlock rear doors ON and OFF 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 and open/high resistance. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, replace the body fuse block.

Repair Instructions

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

* Body Wiring Harness Junction Block Replacement