Powertrain, generic (extended)

P2431 AIR System Air Flow/Pressure Sensor Circuit Range/Performance (Bank 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2431 flags a bank 1 secondary air pressure signal that can be read but makes no sense. The usual check compares the sensor with barometric pressure: with the pump off both should agree, with the pump running the rise must stay within limits. GM sets the code on the 3.8L V6 (2005–2006) when the gap exceeds 10 kPa with the pump off or 50 kPa with it on for over 30 s, Type B; the 2018 table works with 15 kPa and 50 kPa. Volkswagen's 2014 Beetle 1.8 TSI allows a deviation of up to 60 hPa from ambient pressure, the Golf CBFA engine only 25 hPa. GM bulletin PIP4409E links P2431 on Colorado, Canyon and H3 to broken MAP sensor wires, because the comparison relies on a correct baro value. Pure circuit faults go under P2432/P2433.

Likely causes

Pressure sensor drifted or reacts too slowly
Wrong barometric reference, e.g. damaged MAP sensor wiring
Restricted or leaking air duct around the sensor port

Symptoms

  • Check engine lamp, often only after cold starts
  • Secondary air monitor not completed
  • Possibly further MAP or lean codes if the reference is wrong

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–400
Time0.5–2.5 h

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

Parts involved

air system flow sensor b1sai wiring

Related codes

P2430P2432P2433P2436P0411

References: gsi.ext.gm.com, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.