B1421: Passenger Power Window Motor Circuit Short To Ground
What does B1421 mean?
B1421 is a diagnostic trouble code indicating "Passenger Power Window Motor Circuit Short To Ground". The ECU is detecting a voltage reading that is below the expected range in the doors & windows circuit. This typically points to a wiring short, a faulty sensor, or a grounding issue.
Symptoms you may notice
- Check engine light (MIL) illuminated on dashboard
- Intermittent warning lights
- Erratic gauge readings
Estimated repair cost
Typical range in Australia (parts + labour)
Common causes
- Damaged or corroded wiring harness
- Loose or disconnected electrical connector
- Failed doors & windows sensor or actuator
- Blown fuse in the related circuit
- Poor ground connection
What should you do?
This code sits in the body control module or something wired through it. That module runs the unglamorous things you only miss when they stop: headlights, wipers, indicators, central locking. The car will usually drive, but check what has actually stopped working before you rely on it at night or in the wet.
Get a diagnosis for YOUR car
Code B1421 can mean different things depending on your vehicle. TorqueBot gives you a diagnosis specific to your make, model, and year.