This shows a generic code for "Insufficient Coolant Temperature for Closed Loop Fuel Control". Does anyone have an idea which sensor would cause this code? Is it the engine temperature sensor C159 on the radiator? Maybe the engine coolant temperature sensor on the engine C163? Could this be a computer problem? Any help would be appreciated, I have been chasing this for a couple months. I reset the CEL and it's fine for a week or two then it comes back.
97 Explorer 5.0 with P0125 Code
Dec 17, 2006
7 Replies
Is the engine coming up to operating temp? Perhaps it needs a new thermostat...
To be honest, you really need to be a little more sure than "seems".... While it is possible that the ECT is faulty, it is rare that these sensors require replacement. These sensors are a simple thermistor and there's not much that can go wrong with them.
OK.... info is our friend... The ECT and the (IIRC) IAT both share the same line for VREF.... about 4.5 or 5 volts. Since these thermistors react inversely, cooler = higher resistance..... If your IR thermometer shows
200F when you point it at the thermostat housing, you can unplug the ECT and measure the resistance across the two pins.... Expect in the neighbourhood of 2.5K ohms - give or take. If this is good, suspect corroded or spead terminals in the wiring connectors....
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required