⌘K
HomeTrouble codesU0109
Diagnostic trouble code

U0109

0 owner reports and 128 manufacturer filings across 34 model years from Ford, Genesis, Hyundai, Lincoln.

NetworkGeneric OBD-II code128 manufacturer filings

Where U0109 shows up

Source: NHTSA manufacturer communications and complaints
Model yearFiled underBulletinsOwner reports
2019 Ford ExplorerElectrical System9
2018 Ford ExplorerElectrical System9
2021 Ford ExplorerElectrical System6
2021 Ford ExpeditionElectrical System5
2020 Ford ExpeditionElectrical System5
2019 Ford ExpeditionElectrical System5
2018 Ford ExpeditionElectrical System5
2020 Ford ExplorerPower Train5
2020 Ford F-150Power Train5
2020 Ford TransitPower Train5
2019 Ford TransitElectrical System5
2018 Ford TransitElectrical System5
2021 Lincoln AviatorPower Train5
2020 Lincoln AviatorElectrical System5
2021 Lincoln NavigatorElectrical System5
2020 Lincoln NavigatorPower Train5
2019 Lincoln NavigatorElectrical System5
2018 Lincoln NavigatorElectrical System5
2022 Ford ExpeditionElectrical System4
2022 Ford TransitElectrical System4
2022 Lincoln AviatorElectrical System4
2022 Lincoln NavigatorElectrical System4
2023 Ford TransitElectrical System2
2023 Ford Bronco SportPower Train1
2022 Ford Bronco SportPower Train1
2024 Ford ExpeditionUnknown Or Other1
2024 Ford TransitUnknown Or Other1
2020 Genesis G80Fuel System, Gasoline1
2019 Genesis G80Fuel System, Gasoline1
2018 Genesis G80Fuel System, Gasoline1
2017 Genesis G80Fuel System, Gasoline1
2016 Hyundai GenesisFuel System, Gasoline1
2024 Lincoln AviatorUnknown Or Other1
2024 Lincoln NavigatorUnknown Or Other1

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

Electrical System 68Power Train 28Unknown Or Other 27Fuel System, Gasoline 5
Advertisement

Manufacturer filings that name it

Source: NHTSA manufacturer communications

Service bulletins and campaigns whose filed summary names U0109. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.

What U0109 means

Source: SAE J2012 / OBD-II

U0109 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 U0109

Source: NHTSA files and the OBD-II standard

Can I keep driving with U0109 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.