P2D2AHybrid/EV Electronics Coolant Temperature Sensor A/B Correlation
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- Some drives measure the coolant of the inverter and power electronics loop at two points. After a long rest both should read nearly the same, so P2D2A records that sensors A and B disagree by more than the allowed margin; the code does not say which one is wrong. No manufacturer documents P2D2A publicly. GM's 2019 hybrid tables run the idea with one sensor and other references under P0CEF: after at least 3,600 s with compressor, pump and propulsion off, the electronics coolant reading must stay within 27 °C of outside air or transmission fluid, or 28 °C of a refrigerant-based value (Type B). CARB requires inputs of inverter thermal management to be monitored.
- What you may notice
- Hybrid or EV system warning
- Electronics coolant pump runs more often or at full speed
- Possible power reduction to protect the inverter
- Likely causes
- LikelyOne of the two sensors has drifted
- PossibleAdded resistance in a connector or wire shifting one reading
- PossibleAir pocket at one sensor after coolant service
- RareReplacement sensor with a different characteristic
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.