U04A9
0 owner reports and 323 manufacturer filings across 25 model years from Volkswagen.
Where U04A9 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports | Parts |
|---|---|---|---|---|
| 2024 Volkswagen Atlas | Not specified | 48 | — | |
| 2025 Volkswagen Atlas | Not specified | 34 | — | |
| 2024 Volkswagen ID.4 | Not specified | 24 | — | |
| 2023 Volkswagen ID.4 | Not specified | 24 | — | |
| 2023 Volkswagen Tiguan | Not specified | 19 | — | |
| 2022 Volkswagen Tiguan | Not specified | 19 | — | |
| 2024 Volkswagen Tiguan | Not specified | 18 | — | |
| 2023 Volkswagen Atlas | Not specified | 14 | — | |
| 2022 Volkswagen Atlas | Not specified | 14 | — | |
| 2025 Volkswagen ID.4 | Not specified | 12 | — | |
| 2022 Volkswagen ID.4 | Not specified | 12 | — | |
| 2021 Volkswagen ID.4 | Not specified | 12 | — | |
| 2025 Volkswagen Golf / GTI | Not specified | 10 | — | |
| 2024 Volkswagen Golf / GTI | Not specified | 10 | — | |
| 2023 Volkswagen Jetta | Not specified | 7 | — | |
| 2022 Volkswagen Jetta | Not specified | 7 | — | |
| 2025 Volkswagen Taos | Not specified | 7 | — | |
| 2023 Volkswagen Taos | Not specified | 7 | — | |
| 2022 Volkswagen Taos | Not specified | 7 | — | |
| 2026 Volkswagen Atlas | Not specified | 6 | — | |
| 2024 Volkswagen Jetta | Not specified | 4 | — | |
| 2024 Volkswagen Taos | Not specified | 4 | — | |
| 2025 Volkswagen Jetta | Not specified | 2 | — | |
| 2026 Volkswagen Jetta | Not specified | 1 | — | |
| 2026 Volkswagen Taos | Not specified | 1 | — |
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.
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U04A9 by make
The same record, one make at a time: the model years, bulletins and owner reports that name U04A9 on that maker’s vehicles.
What it gets filed under
323 manufacturer filings name U04A9. Start with what the maker wrote down.
A code names the test that failed, not the part. A bulletin that names it is often a diagnosis someone has already written down — quote its number at the service desk.
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names U04A9.
- VIN4APIN20251020 Other2025-10-20 · Unknown Or Other
- Oil leak from Cylinder Head Cover; Customer states MIL-on, P0456, P0442, or P04F0 stored in ECM memory; Customer states MIL-on; Coolant leak from the cylinder head gasket, low coolant level, visible coolant leak, coolant warning message in instrument cluster; Customer states Electrical System Error Message, U04A1 [42304], U04A5 [42336], and/or U04A9 [42444] stored in DA:008C; Customer states vario
- VIN4APIN20251008 Other2025-10-08 · Unknown Or Other
- Oil leak from Cylinder Head Cover; Customer states MIL-on, P0456, P0442, or P04F0 stored in ECM memory; Customer states MIL-on; Coolant leak from the cylinder head gasket, low coolant level, visible coolant leak, coolant warning message in instrument cluster; Customer states Electrical System Error Message, U04A1 [42304], U04A5 [42336], and/or U04A9 [42444] stored in DA:008C; Customer states vario
- VIN4APIN20251001 Other2025-10-01 · Unknown Or Other
- Oil leak from Cylinder Head Cover; Customer states MIL-on, P0456, P0442, or P04F0 stored in ECM memory; Customer states Electrical System Error Message, U04A1 [42304], U04A5 [42336], and/or U04A9 [42444] stored in DA:008C; Customer states various error messages on the cluster; Customer states wind noise and or water ingress; Customer states front brake noise/premature uneven pad wear; Customer sta
- VIN4APIN20250910 Other2025-09-10 · Unknown Or Other
- Oil leak from Cylinder Head Cover; Customer states MIL-on, P0456, P0442, or P04F0 stored in ECM memory; Customer states Electrical System Error Message, U04A1 [42304], U04A5 [42336], and/or U04A9 [42444] stored in DA:008C; Customer states wind noise and or water ingress; Customer states there is a noise coming from the front strut arae; Customer states there is a noise coming from the front strut
- VIN4APIN20250818 Other2025-08-18 · Unknown Or Other
- Oil leak from Cylinder Head Cover; Customer states MIL-on, P0456, P0442, or P04F0 stored in ECM memory; Customer states Electrical System Error Message, U04A1 [42304], U04A5 [42336], and/or U04A9 [42444] stored in DA:008C; Customer states wind noise and or water ingress; Customer states middle row seat rattles; Customer states there is a noise coming from the front strut arae; Customer states ther
- VIN4APIN20250605 Other2025-06-05 · Unknown Or Other
- Customer states MIL-on, P055F stored in ECM memory with message on cluster stating “please warm engine oil to 176 degrees F”; Oil leak from Cylinder Head Cover; Customer states MIL-on, P0087 Stored in ECM memory; Customer states key functions (FOB or KESSY) for lock and/or unlock are inoperative; Customer states windshield wipers activate (swipe) on their own without rain input; Customer states El
What U04A9 means
Source: SAE J2012 / OBD-IIU04A9 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 U04A9
Source: NHTSA files and the OBD-II standardCan I keep driving with U04A9 stored?
Nobody can answer that from the code alone, and a site that does is guessing. A steady light means a fault was logged and the car should be checked soon; a flashing light means a severe misfire — slow down and get it seen as soon as possible, because severe misfire can quickly damage the catalytic converter. 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.