Mirror Driver Vertical Switch Circuit Failure
The vertical control switch in your side mirror isn't sending the right electrical signal to the car's computer, like a light switch that's broken and won't tell the system whether it's on or off. This prevents the mirror from moving up and down properly.
The ECU monitors the voltage signal from the mirror vertical switch circuit to detect valid control inputs. It expects a clean digital or analog signal within specific voltage ranges when the switch is activated. If the signal is absent, shorted, or out of range for too long, the fault is logged.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch Signal Voltage | 0-5V with clean transitions | Out of range, stuck, or no signal detected |
| Circuit Continuity | Continuous path with <5Ω resistance | Open circuit or >10Ω resistance |
Code B1733 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, B1733 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.