Passenger Door Ajar Circuit Failure
Your vehicle's computer detected a problem with the passenger door's sensor circuit that tells it whether the door is open or closed. It's like a light switch that's stuck or broken—the car can't reliably tell if the door is really ajar.
The ECU monitors the passenger door ajar switch for continuity and proper voltage signals. When the door closes, the switch should report a specific voltage state (typically ground or 12V depending on design). If the signal is missing, unstable, or inverted, the ECU logs a circuit failure.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Door Switch Voltage | 0V (closed) or 12V (open) depending on design | Open circuit, short to ground, or erratic voltage transitions |
| Signal Continuity | Stable signal with clean transitions | Intermittent signal loss or resistance out of range |
Code B1327 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, B1327 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.