Door Lock Circuit Open (B1301)
The B1301 code indicates that the Body Control Module (BCM/GEM) has detected an open circuit in the door lock control circuit, typically for the driver's door. This means there is no electrical continuity between the module and the lock actuator, or the actuator itself has an open coil, preventing the power door locks from operating.
1. Commonly Affected Makes
2. Most Common Causes
- Driver door lock actuator with internally open coil
- Damaged, cut, or disconnected wiring in the harness between the BCM and actuator (common in the hinge area or rubber boot)
- Loose, corroded, or backed-out terminals at the actuator or BCM connector
- Blown fuse in the lock circuit power supply (if monitored by the BCM)
- Internal failure of the BCM/GEM output driver
3. Symptoms You Will Notice
- Driver door lock does not operate with power locks
- Other doors may lock/unlock normally
4. Step-by-Step Diagnosis
Check for blown fuses related to door locks.
Inspect wiring and connectors at the driver door hinge area for breaks or corrosion.
Test the door lock actuator by applying power and ground directly; if no click, replace actuator.
Measure resistance between BCM output and actuator; if open, repair wiring.
If wiring and actuator are good, suspect BCM failure.
5. Frequently Asked Questions
Is it safe to drive?▼
Yes, the vehicle is safe to drive, but the driver door lock will not work electrically. You may need to lock/unlock manually.
How much does it cost to fix?▼
Repair costs range from $50 for a fuse or wiring repair to $200-$400 for actuator replacement, and up to $500-$800 if the BCM needs replacement.