Powertrain, generic (extended)

P2438 AIR System Air Flow/Pressure Sensor Circuit High (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2438 is the bank 2 counterpart of P2433: the secondary air pressure signal of the second bank reads above its upper limit. GM mentions P2438 next to P2437 among the codes that block its AIR sensor and flow tests in the 2018 tables, but publishes no row of its own for it, because the engines described there have one air path. For comparison, GM's bank 1 sensor fails above 94–95 % of the 5 V reference. Typical triggers are a signal shorted to supply voltage, an open ground or an internal sensor defect; Audi's R8 V10, which carries a separate bank 2 sensor G610, shows where such a part sits. No public manufacturer document describes the conditions for P2438 itself. While it is stored, the pump and valve tests cannot be judged.

Likely causes

Signal wire shorted to reference or supply voltage
Open ground circuit of the bank 2 sensor
Bank 2 pressure sensor failed internally

Symptoms

  • Check engine lamp
  • Secondary air readiness stays incomplete

Repair estimate

DifficultyMediumDIY possible
Parts and labour€60–450
Time0.5–2.5 h

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

Parts involved

air system flow sensor b2sai wiring

Related codes

P2433P2435P2437P2439

References: gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.