Code result
U0402
Invalid Data Received From TCM
High severity
What it means
A control module is communicating with the transmission control module but receives implausible data — wrong checksum, frozen value, or out-of-range value. Often results in transmission limp-home.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
TCM software bug or outdated calibration
mediumA plausible cause — test and verify before replacing parts.
TCM internal sensor or processing fault
mediumA plausible cause — test and verify before replacing parts.
CAN corruption causing checksum errors
mediumA plausible cause — test and verify before replacing parts.
Related help
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