2016 F150 3.5L XLT w/ 80k miles..
Wrench light then CEL comes on.. scanner reads P0715 which points to input speed sensor. This is an intermittent issue but what baffles me is everytime it happens the radiator fan kicks on full blast. Gauges show no overheating. Anyone else come across this or have any suggestions? Thanks in advance!

 

I'm thinking either a wiring issue with the transmission harness or a transmission leadframe starting to fail. The fan going high speed is probably part of an engine protection protocol.

 

Yeah that's what I was thinking as well just wasn't sure bebecause of the cooling fan issue. Sucks the input speed sensor is no longer on the outside of the tranny. Leadframe problem seems to be a very common issue but of course, no recall. Smh

 

At least the leadframes are now in stock (or short delivery) and not on backorder like they were for some time.

 

very true

 

Also, forgot to mention that this issue doesn't happen nearly as often in the mornings when it's cool outside.

 

I'm having the same issues but it seems to more happen when the transmission is cold. It also seems that in the Texas heat it does more when air conditioning is on . I have tried adding transmission fluid was seem to temporarily help but I'm not really sure. There really should be a recall about this issue as I'm seeing it more and more as a browse the internet
By the way I have a 2015 XLT 5.0

 

The code 715 indicates a wire issue.
Intermittent ground, open or short.
The PCM is getting un-reliable speed indications.
These faults are often temperature and / or vibration sensitive..
Believe the code, it's all you have to run with.
Good luck.

 

Recall is out for the transmission shifting down.
Sticking. 2014 and later models with the 6r80 transmission.

 

2015 F150 XLT 5.0
I JUST changed Lead Frame yesterday.
Truck is shifting through gears so smooth you would think it didn't have a transmission.
Used Ford OEM lead frame. Found on Amazon and they are going fast. Price is going up daily.