Door Ajar Lamp Circuit Failure
The door ajar warning lamp circuit isn't working properly—the ECU can't control or detect the signal to illuminate the dashboard light. It's like a light switch that's broken and won't turn on even when the door is actually open.
The ECU monitors the door ajar lamp circuit voltage and continuity to ensure it can command the lamp on/off based on door switch inputs. It detects open circuits, shorts to ground, and excessive resistance that prevent proper lamp operation.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Lamp Circuit Voltage | 12V when commanded on, 0V when off | Voltage out of range or stuck at one state |
| Circuit Resistance | <5 ohms lamp on, >100k ohms lamp off | Open circuit or short detected |
Code B1323 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, B1323 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.