Mirror Passenger Vertical Switch Circuit Short To Ground
The passenger side mirror's vertical adjustment switch is sending a constant ground signal to the ECU, like a stuck button that won't let go. This prevents the mirror from responding to your up/down commands.
The ECU monitors the voltage signal from the passenger mirror vertical switch circuit. It expects the switch to toggle between high and low voltage states when activated. A short to ground causes the signal to remain at 0V continuously, preventing the ECU from recognizing normal switch commands.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch Signal Voltage | 5V (inactive) to 0V (active) toggle pattern | Constant 0V (stuck at ground) |
| Circuit Resistance | 100-10,000 ohms depending on switch state | Less than 10 ohms (direct short) |
Code B1744 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, B1744 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.