Transmission problems, occasional and mostly on take off

JSUDELL

MEMBER
2014 FORD F-150
3.7L
V6
2WD
AUTOMATIC
125,000 MILES

About a month ago while driving on the highway my transmission seemed to disengage or slip (not sure of the correct terminology ). I was going about 75 mph, and then it felt like the truck had lost power, it was basically coasting. The rpm’s were going up on the gauge as I gave it gas, but the truck was not accelerating. I pulled over shut it off, waited a few minutes and then started it back up again. This happened once more during the trip. The truck ran fine for a day or two, then it happened again, but this time it was as I took off from a stop. This has happened randomly about once every other day. I replaced my transmission fluid and filter and the problem still occurs. Only one time the check engine light came on, and I was able to get it read before it cleared. Currently there is not a check engine light on. The code read P0720, which is output shaft speed sensor. What should I do?

1 Reply

STEVE W.

MECHANIC
13,475 POSTS

P0720 Ford - Output Speed Sensor Insufficient Input. It is commonly a bad sensor connection or bad harness that causes this code. The harness runs from the speed sensor over the top of the transmission and up into the engine harness. The OSS is the rear sensor on the side of the transmission. I would start by removing the connector and checking it for any corrosion, then follow the wires in the harness. You want to look for anything suspicious like breaks in the wires, rubbing, touching or close to the exhaust.

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