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2017 Ford Explorer - deceleration to cool engine

After replacing the torque convertor twice the service engine came on again followed by a message similar to deceleration in progress to cool engine. I was traveling 65MPH and the car slowed to 45 MPH. Dealer claim that the code said high temperature for the transmission. Any assistance would be greatly appreciated.

I am going to start off by saying that I do not own any fords, because my friends who do own fords are always in the dealership fixing issues with transmissions and wiring harnesses. However I would suggest buying your own OBD2 scanner, so you can get your own readings, or even take it to your local auto parts store and have them tell you the code. I’ve had bad experiences where dealerships tell me i have a certain code and they fix something that doesn’t resolve the problem in the long run.

Now the fact that your explorer slowed down to 45 MPH from 65 due to the message that claimed the engine needed cooling is strange. with more air flowing through the radiator at higher speeds, there should be no need for the car to slow down. I would suspect a few things here.

1: You have a bad sensor or faulty wiring somewhere, whether it be a transmission temp sensor or engine coolant sensor, or a wire shorting out.
2: You actually do have a bad transmission or torque converter.
3: The dealership is either A: putting in the wrong model of torque converter, or B: using the wrong transmission fluid.

Out of all those issues, I highly suspect 1. If you have replaced the torque converter twice already (by the way, what are the intervals of miles between them?) I doubt the torque converter is bad again. That’s why there could be a faulty wiring harness or sensor triggering the supposed “high transmission temperature”. It could also be option 3a however I am not familiar with the transmissions ford uses. I do know that ford has there own certification for fluids (Mercon) and that there are many types of Mercon transmission fluids. While this is a long shot theory, it could be that the dealership is putting in the wrong fluid which could be more viscous or less lubricating causing high trans temps.