Passenger Power Window Motor Circuit Short To Battery
The passenger window motor circuit is detecting an electrical short to the battery, meaning excess current is flowing where it shouldn't. It's like a wire touching the positive terminal and causing a dangerous electrical bypass.
The body control module monitors current draw and voltage on the passenger window motor circuit. When it detects abnormally high current or voltage exceeding expected operating thresholds, it logs a short-to-battery fault. The BCM uses a load line test to confirm the fault condition.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Motor Circuit Voltage | 11-14V during operation | Sustained 13.5V+ with high current draw when window not moving |
| Motor Circuit Current | 2-5A during normal window operation | >10A with no motor resistance |
Code B1420 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, B1420 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.