The B1397 OBD2 fault code relates to the Power Door Unlock circuit. This controls central locking functionality. When the circuit short to battery, door locks may not operate properly.

At AIscanAuto, we help drivers quickly identify OBD2 trouble codes, understand their root causes, and find the right fix.

Symptoms

• Door locks not working with remote or switches
• One or more doors not locking/unlocking
• Security system issues

Common Causes

• Failed actuator — worn motor
• a short to battery voltage is present on the circuit — connects the signal line directly to 12V, causing constant high voltage
• Wiring issues — damaged door harness
• Connector problems — corrosion

Step-by-Step Diagnosis

1. Scan with OBD2 tool — Confirm B1397.
2. Test locks — Check all doors.
3. Inspect wiring — Check door harnesses.
4. Test actuator — Listen for movement.

Repair & Solutions

• Replace actuator if faulty.
• Repair wiring.
• Clean connectors.

Related Codes

• B1394 — Power Door Memory Lock Relay Circuit Short To Battery
• B1395 — Power Door Memory Lock Relay Circuit Short To Ground
• B1396 — Power Door Lock Circuit Short To Battery

External References

- OBD2Pros — Complete DTC Reference

About This Guide

This diagnostic article is an original guide created by AIscanAuto for educational and troubleshooting purposes. The technical information about OBD2 DTC codes is based on publicly available automotive diagnostic standards and industry best practices. External links provided in the "External References" section are for additional reading and context only — they do not imply endorsement or ownership of third-party content. All repair procedures should be performed by qualified technicians.