Powertrain, generic · Fuel and air metering

P017A Cylinder Head Temperature Sensor A Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

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. P017A is the general circuit fault without telling low from high. No manufacturer document using exactly this code was found: VW uses P017B/P017C/P017E for its sensor, and Ford's summaries list its own codes. Ford's published summaries still use its own codes P1289/P1290 for this sensor (fault below 0.244 V or above 4.96 V for 5 s). The description rests on CARB and component information. On a sensor fault the control module typically uses a modelled temperature and runs the radiator fan.

Likely causes

Wiring or connector open or corroded
Sensor faulty (moisture in the housing)
Engine control module

Symptoms

  • Check engine light on
  • Coolant temperature warning or wrong gauge reading
  • Radiator fan runs loud or constantly
  • Cold-start problems possible

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–300
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

cylinder head temperature sensorsensor wiringcooling system

Related codes

P017BP017CP017DP017EP0115P0128

References: law.cornell.edu, newtonnet.co.uk, static.nhtsa.gov.