P017ECylinder Head Temperature Sensor A Circuit Intermittent/Erratic
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- The cylinder head temperature sensor A is an NTC thermistor that measures the temperature of the cylinder head metal or of the coolant in the head. Some Ford engines use it instead of a coolant temperature sensor and calculate a coolant value from it; VW group V8 petrol engines use it as sender G407. CARB requires such sensors to be monitored like the coolant sensor. P017E covers intermittent interruptions or an erratic signal. The VW group explicitly uses it for 'open circuit or loose contact', not only for jumps: on Audi and Bentley V8 engines moisture inside sender G407 after O-ring damage makes it fail intermittently, and an improved part has been introduced. Loose contacts and wires broken by heat or engine movement are other causes. The detection logic is not public.
- What you may notice
- Check engine light on
- Intermittent coolant or overheating warning
- Temperature gauge jumps
- Radiator fan intermittently loud
- Likely causes
- LikelyMoisture inside the sensor (O-ring)
- LikelyLoose contact at connector or pin
- PossibleWire broken by engine movement or heat
- RareSensor faulty 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: €50 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.