Dec 23, 2020
Quick tip: If the plug doesn't fit, you might have the wrong part.
I had a check engine light on my '91, and pulled the diagnostic code 116 for Engine Coolant Temperature (ECT) sensor out of range. I decided to check to make sure the sensor was plugged in properly, no pinched or frayed wires, etc., and I found that the plug (round with one square corner) was a little loose, and slid off of the sensor way easier than expected.
On closer inspection, I realized that the plug appeared to have the square corner on the wrong side based on the location of the lock tabs. Also, it appeared that the plug had been notched in order to enable it to fit onto the sensor.
After some searching through images of various sensors on multiple parts store websites, I began to suspect that the sensor installed was actually an Air Charge Temperature (ACT) sensor, not an ECT!
Sure enough, after removal, this is what the ACT looks like:
Compare that to the ECT:
I installed the ECT, and the plug fit right on and locked in the way it's supposed to.
I topped off the coolant and started it up. Check engine light is off, the engine started easier, and runs smoother. It's a good day!
Another quick tip: Never assume that the previous owner had any clue what they were doing when maintaining or repairing the Bronco.
I had a check engine light on my '91, and pulled the diagnostic code 116 for Engine Coolant Temperature (ECT) sensor out of range. I decided to check to make sure the sensor was plugged in properly, no pinched or frayed wires, etc., and I found that the plug (round with one square corner) was a little loose, and slid off of the sensor way easier than expected.
On closer inspection, I realized that the plug appeared to have the square corner on the wrong side based on the location of the lock tabs. Also, it appeared that the plug had been notched in order to enable it to fit onto the sensor.
After some searching through images of various sensors on multiple parts store websites, I began to suspect that the sensor installed was actually an Air Charge Temperature (ACT) sensor, not an ECT!
Sure enough, after removal, this is what the ACT looks like:
Compare that to the ECT:
I installed the ECT, and the plug fit right on and locked in the way it's supposed to.
I topped off the coolant and started it up. Check engine light is off, the engine started easier, and runs smoother. It's a good day!
Another quick tip: Never assume that the previous owner had any clue what they were doing when maintaining or repairing the Bronco.
JFord, David