P2C3CCylinder Head Temperature Sensor B Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P2C3C is stored when the head temperature signal of sensor B drops out briefly or jumps in steps that no mass of hot metal could follow, while the samples on their own may still lie within the valid window. Loose terminals, a wire that touches ground only over bumps or with engine movement, corrosion in the plug and a cracked thermistor are the usual culprits. No manufacturer publicly documents P2C3C; Ford's bulletins for this sensor family deal with P2C38 and P2C39 and point to PCM software. California rules require engine component temperature sensors used for emission control to be monitored much like the coolant sensor. Wiggling harness and plug while watching live data is the most revealing check. A fault that stays low or high stores P2C3A or P2C3B instead.
- What you may notice
- Check engine light that comes and goes
- Jumping head temperature B in live data
- Occasional fan runs or brief warnings without real overheating
- Likely causes
- LikelyLoose or spread terminal in the sensor B connector
- PossibleHarness rubbing on engine parts and shorting only at times
- PossibleCorrosion in the plug
- RareCracked sensor element
- 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: €30 – €350
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.