B3125

DTC B3125, B3130, or B3135

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 Initial Inspection and Diagnostic Overview.

DTC DESCRIPTOR

DTC B3125
Left Front/Driver Door Only Unlock Circuit

DTC B3130
All Door Unlock Circuit

DTC B3135
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 volts.

CONDITIONS FOR SETTING THE DTC

B3125
The BCM detects a fault in the driver door unlock control circuit while commanding the DRIVER UNLOCK relay.

B3130
The BCM detects a fault in the door unlock control circuit while commanding the UNLOCK relay.

B3135
The BCM detects a fault in the door lock control circuit while commanding the LOCK 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.
- The technician issues a scan tool CLEAR DTCs command.

CIRCUIT/SYSTEM TESTING
1. Ignition OFF, disconnect the harness connector C3 at the I/P Fuse Block.
2. Connect a test lamp between the control circuit terminal 42 and ground.
3. Ignition ON, command the Lock 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 does 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 8 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 41 and B+.
7. Command the Unlock 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 I/P Fuse Block.

REPAIR INSTRUCTIONS
Perform the Diagnostic Repair Verification after completing the diagnostic procedure Verification Tests.
Control Module References for BCM replacement, setup and programming Programming and Relearning