P017DCylinder Head Temperature Sensor A 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
- 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. P017D means the signal voltage is too high – the sensor or wire is open or shorted to voltage, and the control module would read an implausibly cold head. Ford's published summaries flag this under its own code P1289 above 4.96 V for 5 s, but a 2019 bulletin for the F-150 and Mustang 5.0 litre names P1289 and/or P017D and replaces the sensor – so at least that calibration also sets the generic code. GM lists P017D only as an exclusion condition in its diesel software. The engine uses substitute values; the radiator fan typically runs constantly.
- What you may notice
- Check engine light on
- Temperature gauge cold or missing
- Radiator fan runs constantly
- Cold-start or idle problems possible
- Likely causes
- LikelySensor faulty (series fault on Ford 5.0 litre 2019)
- LikelyConnector unplugged or corroded, wire open
- RareSignal wire shorted to voltage
- RareEngine control module
- 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 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.