U0240: Communication with entrapment control unit B has been lost
Communication with entrapment control unit B has been lost. Check the car network wiring, its power supply and that control unit.
| Code | U0240 |
|---|---|
| System | Communication network |
| Group | U02xx, Lost communication with control units |
| Type | Generic: it means the same on every make |
How to read and clear U0240 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see U0240 with its description and whether it’s confirmed, pending or permanent.
If the engine stores it over standard OBD, with FREE you read this code with its explanation for nothing and clear it. With PRO you also read the faults of every control unit and clear them in all of them.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before an inspection. It’s all in how to read and clear fault codes and in inspections and OBD.
Similar codes
- U023B The image processing module B is not answering on the car network
- U023C The image processing module C is not answering on the car network
- U023D The left cruise control front distance range sensor is not answering on the car
- U023E The right cruise control front distance range sensor is not answering on the
- U0241 The headlight control unit A is not answering on the car network
- U0242 The headlight control unit B is not answering on the car network
- U0243 The parking assistance control unit B is not answering on the car network
- U0244 Communication with powered running board control unit A is lost
What does code U0240 mean?
Communication with entrapment control unit B has been lost. Check the car network wiring, its power supply and that control unit.
How do you clear U0240?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, U0240 comes back.
Read it on your car
Final OBD reads and clears engine faults through standard OBD for free, each one explained in plain English. With PRO it also reads the faults of every control unit, each make’s own codes included, and clears them in all of them.
