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.
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.
Common causes
- medium
Software version mismatch after replacement
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-2200
- medium
TCM partially failing
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-2200
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does U0304 mean?
U0304 means "Invalid Data Received from Transmission Control Module". It is a generic OBD-II code that points to a fault in the network / communication.
What are the most common causes of U0304?
software version mismatch after replacement; tcm partially failing; gateway module routing can messages incorrectly — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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