P227E: Barometric Pressure Sensor C Circuit Intermittent/Erratic

P227E covers a sensor C signal that jumps although every single value is in range. GM measures this as a string length: the absolute difference between each reading and the one taken 12.5 ms earlier is summed over 80 consecutive readings, and a sum above 152 kPa (2018 diesel) or 150 kPa (supercharged LT4) counts as a failure. Four failures in five one-second samples set the code, as Type B with two trips on the diesel and as Type A on the LT4. Loose terminals, chafed insulation, a cracked sensor housing or interference from nearby actuators are typical triggers. P227C and P227D catch steady shorts, P227B values that are smooth but wrong. The engine normally keeps running on a substitute pressure.

Symptoms

• MIL on, possibly coming and going
• Occasional brief hesitation or uneven boost

Most likely causes

• Loose or corroded terminals in the sensor C connector
• Chafed wiring with intermittent contact
• Interference from ignition or actuator wiring routed nearby
• Sensor C with an unstable internal element

What to check, in order

Start with the simplest. You can tick off each step.

1. Check the connector and the pressure port
2. Gently move the wiring with the engine running and watch whether the reading changes.
3. With the engine off, compare the reading with the atmospheric pressure from the barometric sensor
4. Watch how it changes when starting and accelerating
5. Clean it with a suitable product, or replace it if it does not respond

Good to know

• Repair difficulty: medium
• It affects emissions.

What each character of P227E means

• P: Powertrain: engine and transmission
• 2: Generic code: same on every make
• 2: Fuel injection
• 7E: Specific fault in that system

Frequently asked questions

Can I keep driving with code P227E?

You can drive with caution to a repair shop. Avoid demanding power if the car is in limp mode.

What causes code P227E?

The most common causes are: loose or corroded terminals in the sensor C connector; chafed wiring with intermittent contact; interference from ignition or actuator wiring routed nearby.

Related codes

• P227CBarometric Pressure Sensor C Circuit Low
• P227DBarometric Pressure Sensor C Circuit High
• P227ABarometric Pressure Sensor C Circuit
• P227BBarometric Pressure Sensor C Circuit Range/Performance
• P2230Barometric Pressure Sensor A Circuit Intermittent/Erratic
• P222EBarometric Pressure Sensor B Circuit Intermittent/Erratic

Sources

• gsi.ext.gm.com: 18OBDG04 Engine Diagnostics
• gsi.ext.gm.com: 18OBDG03A Engine Diagnostics

Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.