What it means
The vehicle bus reports loss of communication with image processing sensor B. ADAS functions that depend on this camera (lane keeping, traffic-sign recognition, forward collision warning) may be inhibited.
How it works
Image processing sensor B analyzes camera data and sends its status or processed information to other vehicle modules. U0266 sets when expected network messages from sensor B are missing, so functions that rely on this particular sensor may be inhibited; the code does not by itself prove sensor B is defective.
Common causes
Most likely first.
- Bus wiring open or shorted
- Module without power or ground
- Module failed
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
How to diagnose it
- Scan all modules for current codes and note freeze-frame details and driver-assistance warnings associated with U0266.
- Check whether sensor B is reachable with a scan tool and determine which assistance functions the vehicle reports as unavailable.
- Inspect sensor B's camera area, connector, and accessible wiring for obstruction, impact, moisture, corrosion, or a loose plug.
- Test the sensor's power and ground circuits to the manufacturer's specification.
- If the supplies pass, check the network wiring to sensor B for an open or short and determine whether alignment or calibration is required after repair.
Common fixes
- Remove an obstruction or reconnect sensor B if inspection finds a simple connection issue.
- Repair damaged or corroded wiring to sensor B.
- Restore a failed power or ground feed.
- Replace and configure sensor B after its wiring and supplies test correctly, then complete any required calibration.
Can I keep driving?
Treat assistance features that depend on sensor B as unavailable until communication is restored, and do not rely on lane keeping, sign recognition, or collision alerts. Drive with extra attention and distance, and stop safely if brake or steering warnings also appear.
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.