Power Door Memory Lock Relay Circuit Open
The door lock relay circuit that saves your lock position is broken or disconnected, like a broken switch that can't remember where it was. Your vehicle can't maintain power door locks in their last position when you turn off the engine.
The ECU monitors the power door memory lock relay circuit for proper voltage and continuity. When you turn off the engine, it energizes the relay to hold door locks in their last position. An open circuit means no voltage is detected across the relay, indicating a broken wire, bad relay, or loose connector.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Relay Circuit Voltage | 12V when energized | 0V or no continuity detected |
| Circuit Resistance | Less than 5 ohms | Infinite ohms (open circuit) |
Code B1393 is a low-severity fault. Your vehicle is generally safe to drive to a workshop for diagnosis. However, do not ignore it indefinitely — low-severity codes often indicate developing problems that become expensive if neglected. Book a diagnostic appointment within 2–4 weeks. If you notice any additional symptoms (rough running, power loss, unusual smells), treat it as higher priority.
Once the fault is repaired, B1393 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.