Powertrain, generic (extended)

P2E4C Battery Charger Coupler Temperature Sensor C Circuit Low

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P2E4C says the voltage on the sensor C input has fallen under its lower limit. Low is about the signal; the temperature it implies depends on the element. Volex fits its NACS inlet with NTC thermistors of 100 kΩ at 25 °C and a B value of 4150 K, whose resistance shrinks as they warm, so with a pull-up a very low voltage stands for an absurdly hot contact. Amphenol's NACS inlet watches DC+ and DC- with PT1000 elements instead; there the same low signal reads as implausibly cold. A short to ground pulls the line down whatever the element, and so can water or corrosion bridging the sensor pins. No manufacturer documents P2E4C publicly, and no thresholds are published. Unlike a true overheat verdict (P2E4E), the circuit is suspect here. P2E4D is the high-signal counterpart.

Likely causes

Sensor C signal wire shorted to ground
Water or corrosion bridging the sensor terminals in the inlet or its connector
Temperature element C shorted internally
Measuring input of the evaluating module defective

Symptoms

  • Charging blocked at once or ended shortly after start
  • Charging system warning
  • Fault may follow rain or a car wash

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–1,500
Time0.5–3 h

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

Parts involved

charge port temperature sensorwiring harnesson board charger

Related codes

P2E4AP2E4BP2E4DP2E4EP2E51P0D9B

References: volex.com, amphenol.co.jp, law.cornell.edu.