Powertrain, generic (extended)

P2377 Turbocharger/Supercharger Inlet Pressure Sensor B Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2377 means sensor B ahead of the compressor delivers a voltage above its upper limit. Publicly no manufacturer defines this B code, so GM's P012D for the supercharged LT4 serves as a reference: it trips above 97 % of the 5 V reference, which equals about 124 kPa at that sensor, again with 320 failed samples out of 400 at 12.5 ms intervals and Type B. Upstream of a compressor the pressure cannot rise far above ambient, so such a reading is not physical. Typical faults are a signal wire touching the 5 V supply or battery voltage and an interrupted sensor ground, after which the output rises to the reference. Moisture that has crept into the connector can also create a path to the supply. P2376 is the opposite low-voltage case.

Likely causes

Signal wire shorted to 5 V reference or battery voltage
Sensor ground of sensor B open
Moisture bridging terminals in the connector

Symptoms

  • Check engine light on
  • Implausibly high inlet pressure in live data

Repair estimate

DifficultyEasyDIY possible
Parts and labour€20–300
Time0.3–2 h

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

Parts involved

turbocharger inlet pressure sensor bsensor wiringsensor reference voltage

Related codes

P2376P2374P2375P2378P012D

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