P2C3BCylinder Head Temperature Sensor B Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- With P2C3B the voltage from cylinder head temperature sensor B stays above the valid ceiling, which the module would have to read as a head far colder than any real engine. An interrupted signal wire, a lost sensor ground, a terminal that has backed out of the plug or a thermistor cracked by heat cycling are the typical finds. No manufacturer publicly documents the code. For sensor A, Ford's 2024 OBD summary sets the high-input code above 4.96 V lasting 5 s. With the head temperature gone, the engine control falls back on coolant temperature or a default, may run the fans as a precaution and can keep warm-up settings longer than needed. Measure the voltage at the unplugged sensor first. The ground short case is P2C3A, the general circuit fault P2C38.
- What you may notice
- Live data shows head temperature B at the lowest possible value
- Check engine light
- Fans run more often, idle and warm-up behaviour unusual
- Likely causes
- LikelyOpen signal wire or terminal pushed out of the connector
- PossibleSensor return (ground) circuit open or high resistance
- PossibleThermistor of sensor B broken internally
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €40 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.