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. |
DTC Descriptors
DTC B3125 00: Left Front/Driver Door Only Unlock CircuitDTC B3130 00: All Door Unlock Circuit
DTC B3135 00: All Door Lock Circuit
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
I/P Fuse Block B+ | 1 | 1 | -- | -- |
Left Lock Switch Signal | B3150 00 | B3150 00 | B3150 00 | -- |
Left Unlock Switch Signal | B3140 00 | B3140 00 | B3140 00 | -- |
Door Latch Control | 1 | 1 | 1 | -- |
Doors Unlock Control | B3130 00 | B3130 00 | B3130 00 | -- |
LF Door Unlock Control | B3125 00 | B3125 00 | B3125 00 | -- |
Doors Locked Control | B3135 00 | B3135 00 | -- | -- |
Door Lock Switch Ground | -- | 1 | 1 | -- |
I/P Fuse Block Ground | -- | 1 | 1 | -- |
1. Door Lock Mlafunction | ||||
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 00
The BCM detects a fault in the F/DR LCK relay control circuit.
B3130 00
The BCM detects a fault in the DOOR UNLOCK relay control circuit.
B3135 00
The BCM detects a fault in the DOOR LOCK relay control circuit.
Action Taken When the DTC Sets
The power door locks will not operate.
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
Connector End View Reference
Description and Operation
Power Door Locks Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, command the driver door and passenger door latches to LOCK and UNLOCK with the scan tool, all doors should perform the LOCK and UNLOCK function.
Circuit/System Testing
- Ignition OFF, disconnect the X1 harness connector at the I/P fuse block.
- Connect a test lamp between the control circuit terminal 56 and ground.
- 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.
- Connect a test lamp between the control circuit terminal 54 and B+.
- 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.
- Connect a test lamp between the control circuit terminal 58 and B+.
- 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 all circuits test normal, replace the I/P fuse block.
| ⇒ | 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. |
| ⇒ | 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. |
| ⇒ | 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. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
