Window Driver Rear Remote Up Switch Short to Battery
The rear window's remote control switch is electrically shorted directly to the battery's positive power, causing the ECU to detect an abnormal voltage signal. It's like a wire touching a live power line when it shouldn't be connected at all.
The ECU monitors the voltage signal from the rear window remote up switch, expecting it to toggle between ground and a reference voltage when activated. When the switch is shorted directly to battery voltage, the ECU detects an out-of-range high voltage that doesn't match normal switch behavior patterns.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Switch Signal Voltage | 0V to 5V (toggling between states) | Constant 12V+ (battery voltage) |
| Signal Stability | Clean transitions between states | Stuck at maximum voltage |
Code B2174 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, B2174 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.