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Federal filingsHome›Trouble codes› P1233
Diagnostic trouble code

P1233

2 owner reports and 18 manufacturer filings across 10 model years from Hyundai, Kia.

Powertrain Manufacturer-specific 18 manufacturer filings 2 owner reports

Where P1233 shows up

Source: NHTSA manufacturer communications and complaints
Model yearFiled underBulletinsOwner reportsParts
2019 Kia OptimaFuel/Propulsion System21Fuel pump →
2019 Hyundai SonataEngine2—
2018 Hyundai SonataEngine2—
2017 Hyundai SonataEngine2—
2016 Hyundai SonataEngine2—
2020 Kia OptimaFuel/Propulsion System2—Fuel pump →
2018 Kia OptimaFuel/Propulsion System2—Fuel pump →
2017 Kia OptimaFuel/Propulsion System2—Fuel pump →
2016 Kia OptimaFuel/Propulsion System2—Fuel pump →
2017 Hyundai TucsonFuel/Propulsion System—1Fuel pump →

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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P1233 by make

The same record, one make at a time: the model years, bulletins and owner reports that name P1233 on that maker’s vehicles.

Kia 5Hyundai 5

What it gets filed under

Fuel/Propulsion System 12 Engine 8

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.

Check engine code P1233 stored & retrieved by scanner, indicating fuel pump issue -- (potentially a low pressure fuel pump leak similar to Hyundai TSB 23-FL-004H?), which may present fire hazard from leaking fuel
2017 Hyundai Tucson Jun 6, 2024 NHTSA owner report
After my mechanic inspected my vehicle we received error code P1233 and advised me to call the dealership as this is something covered under an extended warranty
2019 Kia Optima Nov 22, 2023 NHTSA owner report

18 manufacturer filings name P1233. 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.

Photo: Compagnons / Unsplash

Manufacturer filings that name it

Source: NHTSA manufacturer communications

Service bulletins and campaigns whose filed summary names P1233.

What P1233 means

Source: SAE J2012 / OBD-II

P1233 is a manufacturer-specific code: the second character is a 1, which under the OBD-II standard hands the definition to whoever built the vehicle. The same code can mean one thing on a Ford and something unrelated on a Hyundai. Any site that prints a single definition for it is guessing.

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.

From here

Common questions about P1233

Source: NHTSA files and the OBD-II standard

Why does this page not define P1233?

Because it cannot be defined honestly. The second character of a trouble code says who owns its meaning, and a 1 or a 3 hands that to the manufacturer. Sites that print one definition for a manufacturer-specific code are showing you one automaker's meaning and hoping it is yours.

Can I keep driving with P1233 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.