Driver Power Window Up Circuit Open
The driver's power window up circuit has an open connection, meaning the electrical path is broken like a cut wire. The car's computer detected that the window motor isn't receiving proper power when the up button is pressed.
The ECU monitors current flow through the driver power window up circuit when the switch is activated. It expects to detect current draw from the window motor; if no current is sensed within a set timeframe, it logs an open circuit fault. The module uses voltage and amperage thresholds to distinguish between normal operation and a break in the electrical path.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Circuit Current Draw | 8-15 amps during up operation | Below 0.5 amps or no measurable current |
| Voltage at Switch Input | 12V present when up switch activated | Below 10V or intermittent signal |
Code B1407 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, B1407 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.