P227B on Chevrolet: How to Diagnose & Fix
Barometric Pressure Sensor 2 Performance
1 Chevrolet model · 1 documented issue · $200-$2,500 repair
P227B on Chevrolet by model: symptoms, diagnosis and fix
GM released Bulletin #25-NA-239, 'Malfunction Indicator Lamp (MIL) Illuminated - DTC P222B and/or P227B Set,' with fitment limited to 2025 Corvette models equipped with the 5.5L twin-turbo LT7 - that is, the ZR1 only. Both codes are barometric pressure sensor range/performance codes (P222B is Barometric Pressure Sensor 'B' Range/Performance), which on a turbocharged engine with more than one pressure sensor flag a reading that does not agree with the others. Because the bulletin is engine-code specific, this fault cannot occur on the naturally aspirated LT6 Z06, the LT2 Stingray, or the E-Ray.
Common Symptoms
- Check Engine light (MIL) illuminated
- DTC P222B and/or P227B stored in the ECM
How to Fix
Have a Chevrolet dealer read the ECM, confirm P222B and/or P227B, and apply Bulletin #25-NA-239 for the 2025 LT7. Do not let a shop replace parts before the bulletin's diagnostic path has been followed. 2025 ZR1s remain inside the powertrain warranty, so this should be a no-charge repair.
Call to confirm they can assess your vehicle and perform the stated work. Search results do not confirm qualification, eligibility or coverage.
Sources for this issue (2)
P227B code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P227B mean on a Chevrolet?
P227B stands for "Barometric Pressure Sensor 2 Performance." General Motors names this code Barometric Pressure Sensor 2 Performance (in generic SAE terms, Barometric Pressure Sensor "C" Circuit Range/Performance). The ECM cross-checks each barometric pressure input against the others and against modelled ambient pressure. P227B sets when barometric pressure sensor 2 returns an irrational reading — one that is within its electrical limits but does not correlate with the rest of the pressure data. On multi-sensor forced-induction engines this code frequently appears alongside P222B, because the module is comparing several ambient/boost references against each other. On Chevrolet it is documented across 1 model: Corvette.
What are the most common causes of P227B?
The most common causes of P227B are: Failed or drifted barometric pressure sensor 2, Damaged, corroded or loose connector and wiring at the sensor, Blocked or contaminated sensor reference port, Induction system leak, loose charge-air pipe or restricted air filter upsetting the correlation, Software calibration out of date (check for applicable manufacturer bulletins), Faulty ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P227B on a Chevrolet?
Published repair estimates on Chevrolet range from $200 to $2,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.