U0402: Invalid data received from the transmission control module
Another module is receiving impossible or inconsistent data from the automatic gearbox ECU. Often a gearbox sensor, low voltage or software.
| Code | U0402 |
|---|---|
| System | Communication network |
| Group | U04xx, Invalid data between control units |
| Type | Generic: it means the same on every make |
| Can you keep driving? | With care |
What U0402 means
The automatic gearbox control unit shares data such as the gear engaged, lever position and shaft speeds over the network. This code is stored by another module, often the engine ECU, when those messages arrive with out-of-range values or errors. The gearbox unit usually has its own codes that explain the source.
Most common causes
- A faulty gearbox sensor, such as a speed or selector position sensor
- Low or unstable battery voltage
- Loose, corroded or oily gearbox control unit connector
- Damaged network wiring or interference
- Gearbox control unit with the wrong software, for example after replacement
- Faulty gearbox control unit
Symptoms
- Engine or gearbox warning light on
- Harsh shifts or gears not engaging
- Gearbox stuck in one gear (limp mode)
- Gear indicator showing odd information
Can you drive with U0402?
With care You can drive with care, but the gearbox may stick in one gear with little performance. Have it checked soon and avoid towing or pushing the car hard.
Open the bonnetthe in-depth explanation
How to check it
Also read the codes in the gearbox control unit. With the reader, watch the engaged gear and gearbox oil temperature live if your car offers them; a frozen or impossible value helps pinpoint the sensor.
How to read and clear U0402 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 U0402 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
- U0400 Invalid data received
- U0401 Invalid data received from the engine control module (ECM/PCM)
- U0403 The transfer box control unit is sending data that cannot be used
- U0404 The gear gearbox control unit is sending data that cannot be used
- U0405 The cruise control unit is sending data that cannot be used
- U0406 The fuel injector control unit is sending data that cannot be used
- U0415 Invalid data received from the ABS control module
- U0416 Invalid data received from the vehicle dynamics control module
- U0422 Invalid data received from the body control module
What does code U0402 mean?
The automatic gearbox control unit shares data such as the gear engaged, lever position and shaft speeds over the network. This code is stored by another module, often the engine ECU, when those messages arrive with out-of-range values or errors. The gearbox unit usually has its own codes that explain the source.
Can you drive with U0402?
You can drive with care, but the gearbox may stick in one gear with little performance. Have it checked soon and avoid towing or pushing the car hard.
How do you clear U0402?
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, U0402 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.
