Mirror Driver Horizontal Feedback Potentiometer Circuit Failure
The side mirror's position feedback sensor isn't communicating properly with the car's computer. Think of it like a volume knob that doesn't tell the stereo where it actually is—the system can't verify the mirror moved to the right position.
The ECU monitors the potentiometer voltage signal from the mirror's horizontal adjustment motor feedback circuit. It expects a proportional voltage change as the mirror moves left or right. If voltage stays constant, drops out, or reads outside expected range, the ECU logs a fault.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Potentiometer voltage feedback | 0.5–4.5 volts (proportional to position) | Constant, 0V, 5V+, or erratic signal |
| Voltage change rate during movement | Smooth linear change over 1–3 seconds | No change, sudden jumps, or open/short circuit |
Code B2320 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, B2320 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.