⌘K
HomeTrouble codesU0402
Diagnostic trouble code

U0402

5 owner reports and 97 manufacturer filings across 25 model years from Chrysler, Fiat, Jeep, Ram.

NetworkGeneric OBD-II code97 manufacturer filings5 owner reports

Where U0402 shows up

Source: NHTSA manufacturer communications and complaints
Model yearFiled underBulletinsOwner reports
2025 Jeep Grand CherokeePower Train10
2024 Jeep Grand CherokeePower Train10
2016 Jeep CherokeeElectrical System9
2016 Chrysler 200Power Train8
2023 Jeep Grand CherokeePower Train7
2025 Jeep Grand WagoneerPower Train6
2024 Jeep Grand WagoneerPower Train6
2025 Jeep WagoneerPower Train6
2024 Jeep WagoneerPower Train6
2017 Jeep RenegadeElectrical System5
2025 Ram 1500Power Train31
2026 Jeep Grand CherokeePower Train3
2023 Jeep Grand WagoneerPower Train3
2023 Jeep WagoneerPower Train3
2022 Ram 1500Electrical System3
2016 Fiat 500Electrical System2
2017 Jeep CherokeePower Train11
2017 Ram Promaster CityPower Train2
2017 Chrysler 200Power Train1
2018 Chrysler 300Service Brakes1
2022 Chrysler PacificaPower Train1
2017 Fiat 500 XPower Train1
2016 Fiat 500 XEngine1
2018 Jeep RenegadePower Train1
2016 Ram Promaster CityPower Train1

A model year appears here because the code is named in its record, not because every one of these vehicles sets it. Counts are mentions in the federal files, not failure rates — nobody publishes the denominator.

What it gets filed under

Power Train 83Electrical System 12Exterior Lighting 3Engine 2Back Over Prevention 1Service Brakes 1
Advertisement

What owners said

Source: NHTSA complaint database

Owners’ own words, one per nameplate, scrubbed of anything identifying. These are unverified reports filed with NHTSA — they are what was said, not a finding that it was true.

Diagnostic codes recorded include U0402 (invalid data from transmission control module) and U1003 (CAN communication fault)
2025 Ram 1500Jan 10, 2026NHTSA owner report
“Digit-verified cel stored codes p0973 in Tim and in pcm, abs bcm u0418 u0402, u422, alll are stored erased codes, no updates, removed air box to access ground and Tim connector, inspected harness from Tcm to transmission, removed and…
2022 Chrysler PacificaSep 20, 2025NHTSA owner report
OBD code was U0402 (implausible data received from TCM) and (P1DD2 torque request signal from TCM denied)
2018 Jeep Renegadeat 7,000 milesJan 7, 2020NHTSA owner report
Lastly, vehicle threw 3 codes for transmission sensors as well as EGR (U0402, u0402pd, and P1DD2) while casually driving
2018 Chrysler 300at 24,000 milesApr 26, 2019NHTSA owner report

Manufacturer filings that name it

Source: NHTSA manufacturer communications

Service bulletins and campaigns whose filed summary names U0402. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.

What U0402 means

Source: SAE J2012 / OBD-II

U0402 sits in the generic range of the OBD-II standard, so it means the same thing on every vehicle sold in the United States — but WhichTrim does not carry a definition for it and will not invent one. What is on this page is the record: who named it and on what.

A stored code names the test that failed, never the part that caused it. It is the starting point of a diagnosis, not its conclusion — the same code has several possible causes and the cheap one is not always right.

Common questions about U0402

Source: NHTSA files and the OBD-II standard

Can I keep driving with U0402 stored?

Nobody can answer that from the code alone, and a site that does is guessing. A steady light generally means the fault was logged and the vehicle is in a reduced-risk mode; a flashing light means stop soon, because a misfiring engine can destroy a catalytic converter in minutes. The safe read of this page is the mileage and the components, not permission.

Does a code mean the car is recalled?

No. Recalls are filed by campaign and matched by VIN, and none of them are triggered by a scan tool. If you want to know whether an open recall applies to one specific vehicle, check the VIN at nhtsa.gov/recalls — that is the only source that settles it.

Why do the counts here differ from other sites?

Because these are not estimates. Every number on this page is a count of documents in NHTSA's own files: manufacturer communications that name the code in their filed summary, and owner complaints that name it in the narrative. We do not model, weight or extrapolate them.

Will clearing the code fix it?

Clearing turns the light off and erases the freeze-frame data a technician would have used to work out what happened. If the condition is still there the code returns, usually within a few drive cycles, and the diagnosis now starts from less information than before.