Powertrain, generic · Hybrid propulsion

P0C3E DC/DC Converter Temperature Sensor B Range/Performance

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modePossible

P0C3E flags DC/DC converter temperature sensor B as electrically valid but implausible, for instance when it disagrees with sensor A or with what the converter load should produce. FCA uses it on the 2021 Ram 1500 with the 3.6 litre eTorque mild hybrid under the name temperature sensor 2 performance. Bulletin 08-037-21 reflashes the hybrid control processor and changes P0C3E, together with P0C39 for sensor 1, from a two-trip to a one-trip code, so one failed test can light the MIL. CARB requires rationality checks for converter inputs. Typical causes are a drifting element, poor thermal contact or outdated software. Circuit faults of sensor B are reported as P0C3D, P0C3F or P0C40; a converter that is really too hot sets P0D32 instead.

Likely causes

Outdated hybrid control software (Ram 1500 eTorque, bulletin 08-037-21)
Sensor B drifting or with poor thermal contact
Uneven converter cooling making sensors A and B disagree

Symptoms

  • MIL, after one trip with updated Ram software
  • Mild hybrid assist or 12 V supply reduced

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–1,800
Time0.5–4 h

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

Parts involved

dcdc converter temp sensor bwiring harnessdcdc converter

Related codes

P0C3DP0C3FP0C40P0C41P0C39P0D32

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