P0494
1 owner report and 22 manufacturer filings across 13 model years from Buick, Cadillac, Chevrolet, GMC.
Where P0494 shows up
Source: NHTSA manufacturer communications and complaints| Model year | Filed under | Bulletins | Owner reports |
|---|---|---|---|
| 2021 Buick Enclave | Engine And Engine Cooling | 2 | — |
| 2021 Cadillac XT5 | Engine And Engine Cooling | 2 | — |
| 2020 Cadillac XT5 | Engine And Engine Cooling | 2 | — |
| 2021 Cadillac XT6 | Engine And Engine Cooling | 2 | — |
| 2021 Chevrolet Blazer | Engine And Engine Cooling | 2 | — |
| 2020 Chevrolet Blazer | Engine And Engine Cooling | 2 | — |
| 2021 Chevrolet Traverse | Engine And Engine Cooling | 2 | — |
| 2021 GMC Acadia | Engine And Engine Cooling | 2 | — |
| 2020 GMC Acadia | Engine And Engine Cooling | 2 | — |
| 2023 GMC Hummer EV | Equipment | 2 | — |
| 2026 Buick Envision | Unknown Or Other | 1 | — |
| 2021 Buick Envision | Air Bags | 1 | — |
| 2022 GMC Canyon | Electrical System | — | 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.
What it gets filed under
Manufacturer filings that name it
Source: NHTSA manufacturer communicationsService bulletins and campaigns whose filed summary names P0494. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.
- PIT65462026-09-02 · Unknown Or Other
- This Preliminary information describes a condition where engineering is working on a solution to a P0494 DTC stored in the ECM.
- PIT5925B2023-04-24 · Engine And Engine Cooling — Cooling System
- This Preliminary information communicates to the field that water hitting the cooling fans can set a false DTC: P0494Â for the 2022-2024Â HUMMER EV.Â
- PIT5925A2023-03-23 · Equipment — Electrical
- This Preliminary information communicates to the field that water hitting the cooling fans can set a false DTC: P0494Â for the 2022-2023 HUMMER EV.Â
- PIE0657A2022-01-14 · Air Bags
- This engineering information (EI) closure ends the need for further information from technicians in regards to the Check Engine Lamp illuminated on the Driver Information Center (DIC) with P0494 Set.
- 21NA0882021-05-03 · Engine
- This service bulletin provides repair information to correct a customer concern of a Check Engine Light Displayed on Driver Information Center (DIC), Engine Cooling Fan Windmilling, DTC P0494 Set.
- 21NA0882021-05-03 · Engine And Engine Cooling
- This service bulletin provides repair information to correct a customer concern of a Check Engine Light Displayed on Driver Information Center (DIC), Engine Cooling Fan Windmilling, DTC P0494 Set.
What P0494 means
Source: SAE J2012 / OBD-IIP0494 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 P0494
Source: NHTSA files and the OBD-II standardCan I keep driving with P0494 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.