Network
generic / SAE
U0304
Invalid Data Received from Transmission Control Module
The ECU receives messages from the TCM but their content is implausible (e.g. invalid gear, impossible speed). The transmission may switch to limp-home mode and shift quality is degraded.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number3 / 04
Possible causes
- Software version mismatch after replacement medium
- TCM partially failing medium
- Gateway module routing CAN messages incorrectly low
Symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 80–2000 €
- Estimated time: 0.5–6 h
- Component: tcm
- Component: can bus wiring
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012