What it means
A control module has stopped receiving expected messages from door window motor D. The code identifies the communication loss; it does not establish the cause or which window functions are affected.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
Door window motor D is part of the power-window system and may report status to other vehicle modules over the network. U0225 is logged when expected messages from motor D are missing; the code identifies the communication loss rather than proving the motor itself is defective.
Common causes
Most likely first.
- Loss of power or ground to the motor
- Open, shorted, or damaged network wiring or connector
- Failed motor or control module
Symptoms
- Window operation may be unavailable or limited
- A communication fault may be stored; a warning may appear depending on the vehicle
How to diagnose it
- Scan all modules and check freeze-frame data for low voltage or additional network faults that may involve motor D.
- Operate the window controlled by motor D with its available switches and note whether it fails consistently or intermittently.
- Inspect motor D's connector and the door wiring for loose terminals, corrosion, water entry, and damage where the harness flexes.
- Check power and ground at motor D, then test the network wiring for opens or shorts using the vehicle wiring diagram.
- If power, ground, and network wiring pass, test motor D's operation and communication with the manufacturer's procedure.
Common fixes
- Recharge the battery if low system voltage is present.
- Reseat or clean motor D's connector if it is loose or corroded.
- Repair damaged door wiring or a faulty motor power or ground connection.
- Repair a verified network wiring fault affecting motor D.
- Replace motor D or its control component if circuit checks pass and testing confirms failure.
Can I keep driving?
A short drive is generally possible if the window is closed or secured. Avoid driving with it loose or open if that affects your view, and bear in mind it may not close if weather or security becomes a concern.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.