Powertrain, generic (extended)

P2C34 Crankcase Pressure Sensor B Circuit Low

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

Circuit Low means the voltage from crankcase pressure sensor B stays under the lowest value the sensor can deliver, typically because the 5 V reference is missing, the signal wire is shorted to ground or the sensor itself has failed. Maserati's bulletin MAS002969/A for MY21 Quattroporte, Ghibli and Levante with the F160 V6 or F154 V8 lists P2C34 next to the sensor-A codes P051B–P051D. Its checklist covers harness continuity and insulation, bent or corroded pins at sensor and ECM, the intermediate signal connection, and about 5 V between pins 1 and 2 at the sensor plug; the sensor sits on bank 1 of the V6 and bank 2 of the V8. As a yardstick, Ford sets the sensor-A low code P051C below 0.44 V after 5 s. While stored, the crankcase ventilation leak check is blocked.

Likely causes

5 V reference open or shorted to ground
Signal wire shorted to ground or chafed insulation
Crankcase pressure sensor B internally failed
Bent or corroded pins at sensor or ECM

Symptoms

  • MIL on
  • Other sensors on the same 5 V supply may report faults too
  • Usually no driveability change

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–400
Time0.5–2 h

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

Parts involved

crankcase pressure sensor bwiring harnessecm

Related codes

P2C32P2C33P2C35P2C36P051C

References: static.nhtsa.gov, fordservicecontent.com, law.cornell.edu.