U049B: The tachograph module is sending data that cannot be used
The tachograph module is sending data that cannot be used. It is usually that control unit, its power supply or the network wiring.
| Code | U049B |
|---|---|
| System | Communication network |
| Group | U04xx, Invalid data between control units |
| Type | Generic: it means the same on every make |
How to read and clear U049B 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 U049B 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
- U0497 The rear entertainment control unit A is sending data that cannot be used
- U0498 The telephone control unit is sending data that cannot be used
- U0499 The telematic control unit is sending data that cannot be used
- U049A The door control unit A is sending data that cannot be used
- U049C The battery charger control unit is sending data that cannot be used
- U049D The glow plug 2 control unit is sending data that cannot be used
- U049E The direct ozone reduction catalytic converter temperature sensor is sending
- U049F The gearbox range control unit is sending data that cannot be used
- U0401 Invalid data received from the engine control module (ECM/PCM)
- U0402 Invalid data received from the transmission control module
- U0415 Invalid data received from the ABS control module
- U0416 Invalid data received from the vehicle dynamics control module
What does code U049B mean?
The tachograph module is sending data that cannot be used. It is usually that control unit, its power supply or the network wiring.
How do you clear U049B?
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, U049B 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.
