Invalid Data Received From Transmission Control Module
The U0402 code means the vehicle's onboard diagnostic system has detected: Invalid Data Received From Transmission Control Module. This is a moderate severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $50 - $500 (usually the fault behind the bad data, not the network itself)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- Check Engine or related warning light on
- Functions relying on data from the Transmission Control Module may act erratically
- Often intermittent
Probable Causes (Ranked by Likelihood)
- The Transmission Control Module is transmitting, but its data is implausible - often a failing sensor feeding it High
- Intermittent wiring fault corrupting messages Moderate
- Software mismatch after service Moderate
- Failing Transmission Control Module Low
Common Fixes by Vehicle
What techs usually find when diagnosing U0402 on specific vehicles — tap your vehicle for the fix and the exact part:
2003-2014 Chevrolet Silverado/GMC Sierra hard DIY
U0402 (invalid data from TCM) on GM trucks means the ECM sees the transmission control module reporting but with bad data. Common causes: failing TCM internally, low voltage at the TCM, or bad programming after an update. Start by loading the latest TCM calibration (tech2Win or dealer). If that does not clear it and voltage at the TCM is stable, replace and reprogram the TCM.
Labor: 1-3 hours2007-2014 Ford F-150 hard DIY
F-150 U0402 often appears when the transmission is going into limp mode. The TCM is sending data but the data is implausible (for example, gear ratio impossible or output shaft speed out of range). Pull transmission codes with FORScan in addition to generic OBD-II. Often a transmission range sensor or output shaft speed sensor is the real cause -- the TCM is innocent.
Labor: 1-3 hours2005-2012 Dodge Ram 1500 hard DIY
Ram U0402 can be a symptom of TIPM issues affecting TCM power, or an internal TCM fault. Check the TCM fuse and relay in the TIPM first. Verify 12V at the TCM with key on. If power is good and U0402 persists alongside transmission complaints, the TCM may need replacement. On 5-speed 545RFE trucks, the TCM is internal to the transmission and requires trans removal to service.
Labor: 2-4 hoursFrequently Asked Questions
What does U0402 mean?
U0402 means this module IS communicating with the Transmission Control Module, but the data it sends fails plausibility checks. Diagnose the source module first.
Can I keep driving with U0402?
Usually yes for a short period. The affected function may be degraded, and intermittent wiring faults tend to worsen - diagnose soon.
Should I replace the module for U0402?
Not first. Most communication codes are power, ground, fuse, or wiring problems. Replace the module only after those test good - modules are expensive and often require programming.
Mechanics Guide Step-by-step diagnosis
Step-by-Step Diagnostic Procedure
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Scan the Transmission Control Module itself - the invalid data usually traces to a fault code stored there.
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Fix any codes in the source module first; this code often clears with them.
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Check for recent programming or battery-disconnect events.
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If the source module is clean, monitor the specific data value flagged and follow the OEM pinpoint test.
Sources 2
This page is built from documented references. Verify against your own service info before repair work.
- SAE J2012Diagnostic Trouble Code Definitions (defines the generic OBD-II code ranges)
- Cross-checked against the SAE J2012:2002 DTC table (2026-08-27)archived scan of the SAE standard — readable copy, not SAE’s current edition
Commonly Affected Vehicles
- All OBD-II vehicles - network (U) codes are standardized across makes
Related Codes
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