Mine has the same problem. Did you ever fix it?

 

I am headed to tire shop now…. My front two tires are different - this about the time the transmission started acting up from 3rd in D.
thank you for the excellent information- I would never have put the two together.

QUOTE=5280LR3;654353]First thing to look at is the front tires. Need to be same size. right down to the tread depth. I had two front tires same brand, style and size and would not shift past 3rd gear in standard mode. Shifted fine in sport. I found that I had two different tire diameters on the front. One tire with 5/32" tread depth and the other was a spare and had approximately 10/32" tread depth. I swapped out the 10/32" tire with the mate to the 5/32" tire and the transmission shifted perfectly. The computers check wheel speeds and compare to each other and they must be within specification or you'll run into problems similar to what your experiencing.
Get the front tires matching first. Then I'd move onto having the trans fluid & filter changed along with the mechatronic pass through at the same time. Your trans shop should know what that is. Have the transmission adaptations cleared afterwards and see how it acts. If its still not shifting correctly, you may have a shift solenoid plugged or going bad which is fairly common on the 6HP26 transmissions. If the transmission shifts and performs fine in sport mode (no slipping, clunking, etc) I doubt you need to rebuild the trans, but that's what trans shops do. Rebuild/replace transmissions. I'd pop for a set of shift solenoids before a trans rebuild. Truth is they are more likely to be your issue and if they rebuild the trans and find that the solenoids are bad afterwards, you'll most likely have to pay them to go back inside to replace them. Ford solenoids will work in these transmissions. Ford has a license to manufacture their own equivalent to the German ZF 6HP26. I have a set of 2006 Navigator solenoids in my LR3 and they work just fine.[/QUOTE]

 

did you ever figure out what the head lights have to do with the tranny??? I have the issue right now, please advice…

 

Would this be an issue even of your using the factory spare tire with the factory size 19" tires? My wife had a blow out and since I put the spare on it is having the same issue with shifting.

 

Is it a space saver ? , shouldn't be an issue either way as long as the overall diameter is the same.

 

It certainly could if the diameter isn't the same. As I had posted, only a difference of 5/32" tread depth between the 2 front tires caused mine not to shift past 3rd. I'm guessing it's a "limp mode"

 

I think you had other issues….