Window Feedback Out of Range
The car's window control module is receiving a feedback signal that's outside the expected voltage range, like a dimmer switch sending a signal the car doesn't recognize. This usually means the window motor, switch, or wiring has an electrical problem.
The ECU monitors the voltage feedback from the window motor position sensor to verify proper window operation and detect mechanical faults. It compares the feedback signal against calibrated voltage thresholds to determine if the window is moving correctly and within expected limits.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Window Motor Feedback Voltage | 0.5-4.5V (varies by position) | Below 0.5V or above 4.5V |
| Motor Current Draw | 5-20A during operation | Exceeds 25A or drops below 2A |
Code B1237 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, B1237 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.