CR4.2

Hi all,
I have a 2011 Q7 TDI with the towing package and am towing a travel trailer that works out to about 5300lbs when loaded with my stuff. GVWR of the trailer is 6000.

I have towed a slightly lighter trailer with no problems and charge up the hills. Something recently happened on my 2nd trip out with this new trailer when going up a hill. when I say hill, I am talking about hills that might be a mile or two of slow ascent rising 1000-2000 feet. I have plenty of power heading into the hill, but once I start the ascent, the car shifts up to 8th and stays there. Regardless of where I have the accelerator pushed, I don't get any more power and I start losing RPS. I go from 75 to about 45 and down to about 1100-1200 rpms. Shifting into "S" doesnt do anything. Shifting into manual doesnt let me go lower than 8th either. Once I reach the top of the hill, it will still stay in 8th in the descent and doesnt seem to want to go over 65. Put the car in neutral, coast and then re-engage drop down into drive gives me back my gear range.

One work around I found this last weekend was to stay in manual and shift gears going into the hill. Everything works fine when I do that for a couple hours until about 2 hours into the drive where while in manual mode the car decides to shift up to 8th and I am back to the same problem I was just describing.

I have an appointment with Audi this week and they said they are going to look and see if there are any error codes. I wanted to see if anyone here has run into this or has any theories before I go see the dealership.
Thanks!

Jusforfun

Did you try unplugging the trailer lights? Just Plugging in changes the car to towing mode automatically, pulling the plug might establish whether its an electronics problem caused by the trailer module if it reverts to normal.

CR4.2

Haven't tried that. If I did that, I would also lose my trailer brakes since it's all running through that 7 pin or is there a way to just disable the connection the part that make the car think its in tow mode while keeping my brake controller connected?

Jusforfun

No, but at least it was uphill

CR4.2

Dealer saw no error codes and called Audi to see if there were any known problems. They were not aware of anything but they did have the tech update the software on the ECM and TCM. Taking it out this weekend and will see if that fixed it.

On a side note, They gave me a loaner Q5 2.0T while they had my car. No knock on the Q5 because it is a nice vehicle in it's own right, but I appreciated the Q7 so much when I got it back from the dealer Saturday. Such a smooth and solid ride!