U029A: The high voltage battery sensor module is not answering on the car network
The high voltage battery sensor module is not answering on the car network. It is usually that control unit, its power supply or the network wiring.
| Code | U029A |
|---|---|
| System | Communication network |
| Group | U02xx, Lost communication with control units |
| Type | Generic: it means the same on every make |
How to read and clear U029A 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 U029A 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
- U0296 The AC at the DC converter control unit A is not answering on the car network
- U0297 The AC at the DC converter control unit B is not answering on the car network
- U0298 DC to DC converter control unit A is not answering on the car network
- U0299 DC to DC converter control unit B is not answering on the car network
- U029B The traction motor control unit C is not answering on the car network
- U029C The traction motor control unit D is not answering on the car network
- U029D The NOx sensor A is not answering on the car network
- U029E The NOx sensor B is not answering on the car network
What does code U029A mean?
The high voltage battery sensor module is not answering on the car network. It is usually that control unit, its power supply or the network wiring.
How do you clear U029A?
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, U029A 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.
