Mirror Switch Reference Voltage Positive Common Open Circuit
The mirror control switch isn't sending the proper voltage signal to the car's computer, like a dead battery in a remote control. The electrical connection between the switch and the vehicle's power supply is broken or missing.
The ECU monitors the reference voltage supplied to the mirror switch circuit, typically 12V from the battery through a relay or fuse. When this positive voltage line is open or disconnected, the ECU detects an absence of voltage where it should be present. The circuit cannot complete, preventing switch signal transmission to the control module.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Mirror Switch Reference Voltage | 11.5-13.5V (battery supply voltage) | Below 2V or open circuit detected |
| Circuit Continuity | Continuous path from battery positive to switch | Open circuit or broken connection |
Code B2346 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, B2346 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.