B1397 – Power Door Unlock Circuit Short To Battery

The ODBII code B1397 indicates a short circuit in the power door unlock circuit, meaning that the circuit is receiving voltage directly from the battery instead of functioning normally.

The severity of ODBII code B1397 is moderate.

Common Causes For: B1396 Power Door Lock Circuit Short To Battery

• Shorted wiring in the power door unlock circuit
• Faulty door lock actuator
• Malfunctioning door switch
• Corroded or damaged connectors
• Faulty body control module (BCM)
• Improperly installed aftermarket accessories
• Grounding issues in the circuit

Common misdiagnosis for B1397 Power Door Unlock Circuit Short To Battery

• Faulty door lock actuator
• Malfunctioning body control module (BCM)
• Wiring issues or shorts in the harness
• Defective power door lock switch
• Issues with the vehicle’s central locking system
• Battery or charging system problems
• Faulty relay or fuse related to the door locks

Common Troubleshooting Steps

When dealing with OBD-II code B1397, which indicates a “Power Door Unlock Circuit Short to Battery,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Verify the Code: Use an OBD-II scanner to confirm the presence of the B1397 code. Check for any additional codes that may provide more context.
• Inspect the Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors related to the power door unlock circuit for any signs of damage, fraying, or corrosion.
• **Connector Condition: Ensure that all connectors are securely attached and free of dirt or moisture.
• Check for Short Circuits: **Continuity Test: Use a multimeter to check for continuity in the power door unlock circuit. Look for any shorts to ground or battery voltage.
• **Resistance Test: Measure the resistance in the circuit to identify any unexpected low resistance that could indicate a short.
• Inspect the Door Lock Actuator: **Functionality Check: Test the door lock actuator to ensure it is functioning correctly. A malfunctioning actuator can cause a short circuit.
• **Wiring to Actuator: Inspect the wiring leading to the actuator for any signs of wear or damage.
• Check the Power Door Lock Switch: **Switch Functionality: Test the power door lock switch for proper operation. A faulty switch can cause unintended signals to be sent to the actuator.
• **Wiring to Switch: Inspect the wiring connected to the switch for any issues.
• Examine the Body Control Module (BCM): **BCM Functionality: The BCM controls the power door locks. Check for any faults in the BCM that could be causing the issue.
• **Software Updates: Ensure that the BCM software is up to date, as manufacturers may release updates to fix known issues.
• Check for Ground Issues: Ensure that the ground connections for the power door unlock circuit are secure and free of corrosion. A poor ground can lead to erratic behavior.
• Test the System: After performing the above checks and repairs, clear the code using the OBD-II scanner and test the system to see if the code returns.
• Consult Service Manual: If the issue persists, refer to the vehicle’s service manual for specific wiring diagrams and troubleshooting procedures related to the power door unlock circuit.
• Seek Professional Help: If you are unable to resolve the issue after following these steps, consider consulting a professional mechanic or automotive technician for further diagnosis. By following these steps, you should be able to identify and address the cause of the B1397 code effectively.