⌘K
HomeTrouble codesP30CB
Diagnostic trouble code

P30CB

0 owner reports and 59 manufacturer filings across 17 model years from Cadillac, Chevrolet, GMC.

PowertrainManufacturer-specific59 manufacturer filings

Where P30CB shows up

Source: NHTSA manufacturer communications and complaints
Model yearFiled underBulletinsOwner reports
2022 Cadillac CT4Exterior Lighting5
2021 Cadillac CT4Electrical System5
2020 Cadillac CT4Electrical System5
2022 Chevrolet SilveradoElectrical System5
2021 Chevrolet SilveradoElectrical System5
2020 Chevrolet SilveradoExterior Lighting5
2022 GMC SierraElectrical System5
2021 GMC SierraExterior Lighting5
2020 GMC SierraElectrical System5
2023 Cadillac CT4Exterior Lighting3
2023 Chevrolet SilveradoExterior Lighting3
2023 GMC SierraExterior Lighting3
2024 Cadillac CT4Exterior Lighting1
2024 Chevrolet ColoradoExterior Lighting1
2023 Chevrolet ColoradoExterior Lighting1
2024 GMC CanyonExterior Lighting1
2023 GMC CanyonExterior Lighting1

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

Exterior Lighting 32Electrical System 15Engine And Engine Cooling 12
Advertisement

Manufacturer filings that name it

Source: NHTSA manufacturer communications

Service bulletins and campaigns whose filed summary names P30CB. Quoting the document number at a service desk is often the fastest route to a diagnosis someone has already written down.

What P30CB means

Source: SAE J2012 / OBD-II

P30CB is a manufacturer-specific code: the second character is a 3, 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.

Common questions about P30CB

Source: NHTSA files and the OBD-II standard

Why does this page not define P30CB?

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 P30CB 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.