Powertrain, generic · Hybrid propulsion

P0CEE Hybrid/EV Electronics Coolant Temperature Sensor A Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

Sensor A reports the coolant temperature in the loop that cools the hybrid power electronics. P0CEE is the general circuit code for it, used where a controller does not tell low from high. No manufacturer documents this code publicly; GM, for example, reports the same sensor only through P0CF0 (below 2 or 4 % of the reference voltage), P0CF1 (above 98 %) and the plausibility and noise checks P0CEF and P0CF2. CARB requires temperature inputs of inverter cooling systems to be checked for open circuits and for readings outside their valid band, so a controller may file an open or shorted sensor here instead. Because the system can no longer judge the coolant, it usually runs the pump harder and caps inverter and charging power as a precaution.

Likely causes

Loose, corroded or water-soaked sensor connector
Damaged signal or ground wire of the sensor
Failed temperature sensor element

Symptoms

  • Malfunction indicator lamp or hybrid system warning
  • Electronics coolant pump runs continuously
  • Reduced drive or charging power as a precaution

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€40–400
Time0.5–2 h

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

Parts involved

hybrid electronics coolant temp sensor awiring harnesshybrid control module

Related codes

P0CEFP0CF0P0CF1P0CF2P2B20

References: law.cornell.edu, gsi.ext.gm.com.