P2B27Hybrid/EV Electronics Coolant Temperature Sensor C Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2B27 is logged when sensor C in the power electronics coolant loop sends a signal near the top of the reference, which the controller would have to read as deep frost. Far more often than real cold, the reason is a circuit that has opened: a connector that has backed out, a terminal pushed out of its cavity, a broken wire near a moving part or a failed element; shorting to the battery feed is rarer. No manufacturer documents P2B27 publicly; NTN-SNR names an excessive sensor C signal. As an order of magnitude, GM flags its sensor A above 98 % of the reference (P0CF1). CARB counts these sensors as monitored inverter cooling inputs. Unlike the low fault, a cold reading can hide real heat, so the controller usually switches to a substitute value and limits power. P2B26 is the grounded counterpart.
- What you may notice
- Warning lamp and hybrid system message
- Sensor C shown far below outside temperature in live data
- Limited electric power
- Likely causes
- LikelyConnector backed out, terminal pushed out or wire broken
- PossibleSensor C element open
- RareSignal line shorted to battery voltage
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €30 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.