Powertrain, generic (extended)

P2CA7 DC/DC Converter Temperature Sensor E Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2CA7 means the signal of DC/DC converter temperature sensor E is stuck above its upper limit. In a thermistor input fed through a pull-up resistor, an interrupted loop lets the voltage rise to the reference, so a pin pushed out of the connector, a broken conductor or a short to a supply line gives this result. The implied reading would be colder than any real surroundings. No manufacturer documents P2CA7 publicly; the converter sensors named in bulletins stop at letter D. CARB asks for range checks on such hybrid inputs. As a false cold value could hide real heat, the controller treats the temperature as unknown and limits the converter, leaving more of the 12 V load to the battery. P2CA6 is the low-side counterpart.

Likely causes

Open circuit in the sensor E signal or return line, e.g. pushed-out pin
Signal line shorted to a supply voltage
Thermistor of sensor E broken (open)

Symptoms

  • MIL and hybrid or charging warning on
  • Implausibly cold converter temperature in live data
  • Reduced converter output, 12 V battery charge drops

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 ewiring harnessdcdc converter

Related codes

P2CA5P2CA6P2CA8P2CABP2C8FP0E5B

References: law.cornell.edu, patents.google.com, static.nhtsa.gov.