P2227: How to Diagnose & Fix — Barometric Pressure Sensor "A" Circuit Range/Performance
3 vehicles · 3 makes · $150-$1,100 repair
How to diagnose and fix P2227: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
GMC Terrain · 2018–2024
On the second-generation Terrain (2018+) with the turbocharged 1.5L LYX/LSD or 2.0L LTG engine, the air-to-air charge air cooler (intercooler) accumulates condensate from humid or rainy driving plus PCV-borne moisture. In cold ambient temperatures that water freezes inside the CAC core, restricting charge airflow. GM documents this in service bulletin 18-NA-020, first released in January 2018 and later expanded through the 2024 model year. Owners on the Terrain/Equinox forum describe ice and standing water inside the charge tube. Here the cooler itself is blocked by ice or contamination; the duct has not come off the throttle body.
Common Symptoms
- Check engine light in cold weather
- Reduced engine power message
- Rough running and misfire
- Loss of boost / sluggish acceleration
- Water or ice found inside the charge pipe
How to Fix
Follow 18-NA-020: leak-test the CAC, thaw and clean a non-leaking contaminated cooler, and install only the thermostatic shutter the bulletin specifies for the vehicle's engine and climate. A universal intercooler or grille insert is not the prescribed repair.
Sources for this issue (3)
Chevrolet Equinox · 2018–2022
On 1.5L turbo (LYX) Equinox models, moisture accumulates inside the charge air cooler (intercooler) and, in cold or highly humid weather, can freeze or pool enough to severely restrict intake airflow. This trips turbo underboost/MAP faults and pushes the engine into 'Engine Power Reduced' limp mode with sluggish acceleration. A related GM TSB also documents the charge air cooler outlet tube separating from the throttle body on 2018-2022 1.5L turbo models, producing the same reduced-power symptom. This is distinct from the known coolant-loss/intercooler-condensation head-gasket issue — here the failure is airflow restriction and boost loss, not coolant consumption.
Common Symptoms
- Engine Power Reduced warning / limp mode
- Loss of acceleration and turbo boost
- Worse in cold or humid weather
- Check engine light
How to Fix
Inspect and reseat or replace the charge air cooler outlet duct/clamp at the throttle body per GM TSB; clear accumulated condensate from the intercooler; verify the CAC and ducting for cracks. Reprogram the ECM if a related calibration update applies. For cold-weather freezing, GM bulletin 18-NA-020 calls for blocking cold air from the charge air cooler (CAC shutter or lower grille cover), thawing and washing out a frozen CAC, and an ECM calibration update on 1.5L (LYX) engines.
Sources for this issue (3)
- GM Bulletin 22-NA-224 - Reduced Engine Power, DTCs P0101/P0172/P0299/P0506/P1101 (CAC outlet tube separated from throttle body), Equinox 1.5L LYXtsb
- GM Bulletin 18-NA-020 - Poor Engine Performance in Extremely Cold Weather, DTCs P0300/P0299/P0234/P2227 (moisture freezing in charge air cooler)tsb
- GM PIP5651A - Charge Air Cooler Outlet Hose Disconnected From Throttle Body, 2019 Equinox 1.5L LYXtsb
Buick Envision · 2016–2020
The 2.0L LTG turbo's air-to-air charge air cooler collects condensate in its lower core. After long drives in rain or high humidity (heavy fog), a hard throttle application can draw the accumulated water into the engine, causing a sudden multi-cylinder misfire (P0300) and a stumble; in cold weather the moisture can freeze inside the cooler, restricting flow and setting underboost codes P0299/P2227. GM issued TSB 18-NA-020 with a charge air cooler replacement procedure specifically for moisture-related MIL complaints. This affects only the turbocharged LTG cars, not the naturally aspirated 2.5L LCV.
Common Symptoms
- Sudden stumble or misfire on hard acceleration
- Check engine light with random misfire code P0300
- Momentary loss of boost or power
- Worse after long drives in rain or high humidity, or in cold weather
How to Fix
Confirm the misfire pattern is not ignition or injector related, then perform GM TSB 18-NA-020: wipe residual moisture from the boost sensor, smoke-test the charge air cooler, and replace it with the newly designed (wider) part plus the new lower baffle if it leaks or if the vehicle was built on or before January 5, 2019; later builds with no leak go to further diagnosis. Check the intercooler outlet duct for standing water during diagnosis. The bulletin repair is billed under powertrain coverage.
Sources for this issue (2)
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P2227 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 P2227 mean?
P2227 stands for "Barometric Pressure Sensor "A" Circuit Range/Performance." Generic code. The barometric pressure sensor 'A' is connected but its reading is out of range or doesn't track expected atmospheric pressure — the value is absent, inconsistent, or implausible versus other pressure sensors and known altitude.
What are the most common causes of P2227?
The most common causes of P2227 are: Drifting/aging BARO or MAP sensor, Vacuum or pressure reference problem, High-resistance wiring/connector, Sensor contamination, Intermittent reference voltage. The specific cause varies by vehicle.
How much does it cost to fix P2227?
Repair costs for P2227 range from $150 to $1,100, depending on the vehicle and root cause.
Which vehicles are affected by P2227?
Au7o has documented P2227 across 3 vehicle models from 3 manufacturers: Buick, Chevrolet, GMC.
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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.