Lights, screens and comfort
Power windows or central locking failing: what it could be
If a window will not go up or down, or the central locking does not work on every door, the fault is usually in that door's motor or mechanism, its switch or the wiring that runs through the hinge. If several things fail at once, it points to the battery voltage or the body control unit.
Check without hurryLights, screens and comfort
Reviewed by Daniel Morales, founder of Reprorace SL, on
Is it serious? Can I keep driving?
Usually not urgent, but do not ignore it. It is not dangerous to drive, but it is a security issue: a window that will not close or a door that will not lock leaves the car open. If a door will not open from the inside, do not rely on it as an exit and get it fixed soon.
A careful, general answer: only someone who inspects the car can say whether it is safe to drive. When in doubt, stop somewhere safe and call for assistance.
Most likely causes
- Window regulator or motor: the motor whirs but the glass does not move, or nothing happens.
- Door switch: fails from one switch and works from the other.
- Wiring in the door hinge: the wires break after years of opening and closing.
- Door lock actuator: stops working on that door.
- Low battery or body control unit: if several functions fail at the same time.
Listed from more to less common in general; on your car they may be different. A fault-code reading and a check at the garage confirm which one it is.
To understand it better: What do U codes and lost communication (U0100) mean? How can you tell if the 12 V battery is failing?
Car system: CAN network and modules
What you can check yourself
Try the window from both switches (the driver's and the door's own).
Listen for the motor when you press: if it whirs and nothing moves, it is mechanical.
Check whether the remote locks and unlocks the doors from close by and whether its battery is good.
Notice whether other electrical things fail at the same time.
Safe checks only: with the engine off and cold whenever you look under the hood, without taking anything apart and without touching hot or moving parts.
Related fault codes
- U0140Lost communication with body control module
- U0141Lost communication with body control module A
- U0214Lost communication with remote function actuation module
- P0562System voltage: too low
Generic codes that often come with this symptom. Seeing one does not confirm the cause: it is where the diagnosis starts.
How the ECO-LITE helps diagnose it
Plugged into the OBD socket, the ECO-LITE reads the fault codes of the control units that answer, with the freeze-frame data captured when the fault happened, and shows live data on your phone or computer. With your permission, your garage can see them remotely before you bring the car in.
What to look at here: codes from the body control unit and communication with it, and battery voltage.
Frequently asked questions
Do the windows need resetting after disconnecting the battery?
On many cars, yes: the one-touch function stops working until it is done. The owner's manual explains how.
Why does the locking work with the key but not the remote?
It is usually the remote's battery or a reception fault; otherwise, the body control unit.
Can I close a stuck window by hand?
Sometimes it can be lifted carefully while pressing the switch. If not, cover it and take it to a shop.
Keep reading
- CAN network and modules: how they work and what fails
- Car battery keeps going flat: causes and what to do
- Key or immobilizer light: the car does not recognize the key
- Car radio or screen turns off by itself: why
- Car symptoms: what they mean and what to do
- Check engine light on: what to do
- How to read and clear your car's fault codes
- OBD fault codes: what each one means