Powertrain, generic (extended)

P227E Barometric Pressure Sensor C Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

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.

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

Symptoms

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

Repair estimate

DifficultyMediumDIY possible
Parts and labour€30–400
Time0.5–2.5 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

barometric pressure sensorsensor wiring

Related codes

P227CP227DP227AP227BP2230P222E

References: gsi.ext.gm.com, gsi.ext.gm.com.