P017C code meaning
Cylinder Head Temperature Sensor A Circuit Low
Powertrain system Generic code P01xx codes Check engine light
What P017C means
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 gasoline engines use it as sender G407. CARB requires such sensors to be monitored like the coolant sensor. P017C means the signal voltage is too low – a short to ground of the signal wire or a short inside the sensor; the control module would read an implausibly hot cylinder head. 'Low' refers to the signal, not the temperature. Audi and Bentley document it as a short to ground, most often caused by water inside sender G407 after O-ring damage. Ford flags the same condition on its own code below 0.244 V for 5 s. A substitute value is used; an overheating warning with a cold engine is a typical sign.
P017C at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P017C
- Check engine light on
- Overheating or coolant warning despite a cold engine
- Radiator fan runs constantly
Common causes of P017C
- Most likelyWater or coolant inside the sensor (O-ring damaged)
- PossibleSignal wire chafed against ground
- PossibleSensor shorted internally
- Less likelyEngine control module
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Cylinder head temperature sensorSensor wiringCooling system
What each part of P017C means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 1 | Area: fuel and air metering. |
| 7C | The exact fault in that area. |
What to do next
- Note P017C and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P017C
What does P017C mean?
P017C means "Cylinder Head Temperature Sensor A Circuit Low". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P017C?
Drive gently and only to a workshop. With P017C the car can go into limp mode (reduced power) to protect itself.
Will P017C fail an emissions test?
Yes, it can. P017C is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P017C to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will P017C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.