Powertrain, generic

P0E5B DC/DC Converter Temperature Sensor C Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P0E5B is stored when the signal of DC/DC converter temperature sensor C rises above its valid window. On an NTC circuit with pull-up resistor, that is the typical picture of an unplugged connector, a broken wire or a short to a supply voltage, and it reads as a converter far colder than possible. No manufacturer documents P0E5B publicly. Ford's limit for its sensor C, the boost converter inductor sensor, lies at 4.86 V; above that a fault is logged, yet Ford reports it as P0E59. Range checks of this kind are mandatory under CARB for hybrid inputs. Since a cold reading would hide real overheating, the controller treats the converter temperature as unknown and usually limits power. A connector check is the obvious first step. P0E5A is the low-signal counterpart.

Likely causes

Connector unplugged or sensor wire broken
Signal shorted to a supply voltage
Thermistor open internally

Symptoms

  • Hybrid system warning
  • Power limited as a precaution

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€80–2,500
Time0.5–5 h

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

Parts involved

dcdc converter temp sensor cwiring harnessdcdc converter

Related codes

P0E58P0E59P0E5AP0E5CP0C3BP2C8F

References: law.cornell.edu, fordservicecontent.com.