U0099: The vehicle communication bus H (low line) gives a higher signal than normal
The vehicle communication bus H (low line) gives a higher signal than normal. It is usually the part, its wiring or a connector with poor contact.
| Code | U0099 |
|---|---|
| System | Communication network |
| Group | U00xx, Communication buses |
| Type | Generic: it means the same on every make |
How to read and clear U0099 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 U0099 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
- U0095 The vehicle communication bus H (high line) gives a lower signal than normal
- U0096 The vehicle communication bus H (high line) gives a higher signal than normal
- U0097 The vehicle communication bus H (low line) has a broken or disconnected wire
- U0098 The vehicle communication bus H (low line) gives a lower signal than normal
- U009B There is a fault in vehicle data network I
- U009D There is a fault in vehicle data network J
- U0001 High speed CAN communication bus
- U0073 Control module communication bus A off
What does code U0099 mean?
The vehicle communication bus H (low line) gives a higher signal than normal. It is usually the part, its wiring or a connector with poor contact.
How do you clear U0099?
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, U0099 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.
