Door Ajar Circuit Failure
The car's door ajar sensor circuit isn't working properly, so the system can't tell if a door is open or closed. It's like a light switch that's broken and won't send a signal when you flip it.
The ECU monitors the door ajar switch circuit voltage to detect open/closed door states. Each door sends a signal through a switch contact; the ECU expects specific voltage levels when doors are open versus closed. A circuit failure means the ECU receives no signal or an invalid signal.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Door Switch Voltage | 0V (closed) or 12V (open) | Stuck voltage, no response, or intermittent signal |
| Circuit Resistance | <5 ohms (closed) | >10 ohms or open circuit |
Code B1563 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, B1563 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.