Genuine Honda Prelude Coolant Temperature Sensor

Honda Prelude Coolant Temperature Sensor Parts Questions & Answers

• Sensor Assembly, Water Temperature (Hadsys)
  37870-PK2-015
  Q: What is the purpose of the Engine Coolant Temperature (ECT) sensor for the Honda Prelude?

  A: The Engine Coolant Temperature (ECT) sensor works as a thermistor whose resistance varies with coolant temperature. Hence ECT determines how much fuel is going to be mixed with air into the engine. The engine will lose its power and stop if it is unplugged. So you should measure the ECT sensor resistance while the engine is cold and hot to perform this test. In other words, it should read 5000 ohms once it is cold then 100-400 ohms in its hot state. This could mean that the sensor may not be working properly. Disconnecting the battery, draining the coolant, removing the old sensor, and installing a new one with Teflon sealant will facilitate replacement. Top off the coolant, start the engine, and check for leaks afterwards.