Powertrain, generic

P0EC1 A/C Refrigerant Temperature Sensor B Circuit

Check engine lightUsually off
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

P0EC1 covers a circuit fault of a second refrigerant temperature sensor, found mainly on electrified cars whose heat pump or battery chiller measures the refrigerant at several points. The module receives no usable value from sensor B. No manufacturer publishes P0EC1 or says which of its sensors counts as B. Volkswagen's e-Golf shows how such networks look: up to five combined pressure/temperature senders (G395, G826 to G829) share two LIN lines, and because early parts could not be auto-addressed, bulletin 87-17-02 requires replacing every sender on the affected line. Without B the heat pump or A/C may shut down. Detailed faults of sensor B: P0EC2 to P0EC4; sensor A: P0EBC.

Likely causes

Failed sensor B or combined pressure/temperature sender
Wiring, connector or shared LIN line fault
Mixed part versions on one LIN line after a repair

Symptoms

  • Heat pump or A/C switched off or limited
  • Fault stored in the climate control module

Repair estimate

DifficultyShop_onlyWorkshop job
Parts and labour€120–700
Time1–3 h

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

Parts involved

ac refrigerant temp sensor bhvac control modulewiring harness

Related codes

P0EC2P0EC3P0EC4P0EBC

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