How a Ford Coolant Temperature Sensor Works

Written by john albers
  • Share
  • Tweet
  • Share
  • Email

Ford engine coolant temperature sensors, or ECTs, are devices designed to measure the temperature of the liquid coolant passing through the Ford engine block. In this way, the vehicle can get some idea of the engine temperature and adjust both coolant and fuel flow accordingly.

Other People Are Reading


Most modern Fords have the ECT mounted in the neck of the output valve at the back of the engine, where coolant leaves the engine to head back to the radiator. A strip of semi-conductive ceramic or polymer material is suspended in the centre of the outlet valve's neck ring. On each end of the strip is a wire lead which runs back to the on-board computer in modern vehicles or the power train control module in later model Fords. The on-board computer or PCM is typically located in the engine compartment on the passenger side on most Fords.

How Does It Work?

When the Ford is started, coolant passes over the strip of semi-conductive material. A steady current is passed from the computer or PCM through the strip and back. The Ford ECT is technically considered a thermistor in that its resistance to conducting electricity changes as it heats up. When the engine is cold, most of the electricity passing through the ECT is lost due to resistance. The PCM or on-board computer interprets this lack of return electricity as a cold engine and increases the gas in the fuel injector's fuel-air ratio for a richer mix to ensure the engine keeps running. As the car heats up, so does the coolant passing through it and the ECT. This allows a greater amount of electricity to pass back to the PCM or on-board computer. The response is then to thin the fuel mixture to keep the engine from overheating.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.