Powertrain, generic (extended)

P2E55 Exhaust Pressure Sensor C Circuit Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P2E55 is the plausibility test of exhaust pressure sensor C: the voltage is in range, but the pressure does not suit the operating state. CARB wants such rationality faults stored apart from circuit faults. No maker documents P2E55; Ford's 2023 diesel summary shows the pattern for sensor A. With the engine stopped for at least 10 s the reading may differ from ambient pressure by no more than 15 kPa; while driving it is set against a model and may not exceed it by 500 kPa or fall 100 kPa below it. A Ford patent (US7779633) computes the pressure ahead of the turbine; a Bosch patent checks two sensors on either side of a flow restriction against a modelled pressure drop. FCA warns that real back pressure from a clogged particulate filter sets the code on Cummins diesels, so check the exhaust first.

Likely causes

Real back pressure from a clogged particulate filter or catalyst
Sooted or cracked sensing tube to sensor C
Sensor C offset drifted or stuck mid-range
Exhaust leak near the measuring point

Symptoms

  • MIL, often without noticeable driveability change
  • Particulate filter or EGR codes alongside
  • Reduced power if the pressure is really too high

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€60–1,200
Time0.5–4 h

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

Parts involved

exhaust pressure sensor cwiring harnessecm

Related codes

P2E54P2E56P2E57P0471P047B

References: fordservicecontent.com, image-ppubs.uspto.gov, image-ppubs.uspto.gov, static.nhtsa.gov.