Mirror Passenger Horizontal Switch Circuit Failure
The passenger side mirror's horizontal (left-right) adjustment switch isn't communicating properly with the car's computer, similar to a broken remote control that can't send its signal. The ECU detects an electrical fault in the circuit that controls the mirror's side-to-side movement.
The ECU monitors the voltage signal from the passenger mirror horizontal switch circuit. It expects a clean digital or analog signal when the button is pressed, with proper voltage transitions between positions. A fault occurs when the signal is absent, stays at an abnormal voltage level, or shows no response to switch input.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch Signal Voltage | 5V (or 0V-5V logic transitions) | No voltage change or stuck at 0V/12V |
| Circuit Resistance | Less than 10 ohms per connection | Greater than 50 ohms or open circuit |
Code B1745 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, B1745 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.