Powertrain, generic (extended)

P2A0D Manifold Absolute Pressure Sensor B Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2A0D is the high-voltage counterpart: the MAP B signal sits close to the reference voltage. Typical reasons are an open ground wire, a signal wire shorted to the 5 V reference or to battery voltage, or a sensor that has failed internally. For the Corvette's LT6 V8, GM sets P2A0D when the bank-2 manifold pressure sensor reads above 4.5 V for 1.5 s, after a single trip; the bank-1 sensor uses P0108 with practically the same limit. Such a voltage would stand for a pressure that the naturally aspirated intake cannot reach, so the module discards the value and works with a modelled pressure instead. Expect the warning light and, depending on the calibration, rough running or limited power.

Likely causes

Sensor ground wire open or connector not seated
Signal wire shorted to the 5 V reference or battery voltage
Sensor B failed internally

Symptoms

  • Check engine light on
  • Rough running or hesitation
  • Possible limited power

Repair estimate

DifficultyEasyDIY possible
Parts and labour€30–250
Time0.3–1.5 h

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

Parts involved

map sensor bwiring harnessecm

Related codes

P2A0AP2A0BP2A0CP2A0EP0108

References: law.cornell.edu, gsi.ext.gm.com, gsi.ext.gm.com.