U01BB: The onboard charger control unit B is not answering on the car network
The onboard charger control unit B is not answering on the car network. It is usually that control unit, its power supply or the network wiring.
| Code | U01BB |
|---|---|
| System | Communication network |
| Group | U01xx, Lost communication with control units |
| Type | Generic: it means the same on every make |
How to read and clear U01BB 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 U01BB 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
- U01B7 The switch input module A is not answering on the car network
- U01B8 The switch input module B is not answering on the car network
- U01B9 The switch input module C is not answering on the car network
- U01BA The gearbox park lock control unit is not answering on the car network
- U01BC The intercooler B water pump is not answering on the car network
- U01BD The DC DC converter control unit C is not answering on the car network
- U01BE The traction motor clutch actuator A is not answering on the car network
- U01BF The battery management control unit is not answering on the car network
- U0100 Lost communication with engine control module (ECM/PCM A)
- U0101 Lost communication with transmission control module (TCM)
- U0102 Lost communication with transfer case control module
- U0103 Lost communication with the gear shift module
What does code U01BB mean?
The onboard charger control unit B is not answering on the car network. It is usually that control unit, its power supply or the network wiring.
How do you clear U01BB?
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, U01BB 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.
