Powertrain, generic (extended)

P2A0A Manifold Absolute Pressure Sensor B Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

Engines with two intake manifold pressure sensors call the second one sensor B; in GM's tables for the Corvette's LT6 V8 it measures the manifold pressure of bank 2, next to the bank-1 sensor that uses the familiar P0105–P0109 codes. P2A0A is the general circuit fault of sensor B, meant for cases where the module sees a circuit problem without sorting it into low, high or intermittent. No manufacturer documents P2A0A publicly – the LT6 tables split electrical faults of this sensor into P2A0C and P2A0D. CARB requires checks for broken circuits and implausible extremes on every input that affects emissions. Without a usable MAP B signal the module estimates the air charge of the affected bank from a model, which can cost smoothness and power.

Likely causes

Loose connector, corroded terminal or damaged wire at sensor B
MAP sensor B failed internally
5 V reference shared with other sensors pulled down

Symptoms

  • Check engine light on
  • Uneven running or hesitation
  • Possible reduced power

Repair estimate

DifficultyEasyDIY possible
Parts and labour€40–250
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

P2A0BP2A0CP2A0DP2A0EP0105

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