Towing Uphill - check engine light - power stops

[btatro]

I am new to the Diesel world having bought a low miles '05 F250 with the 6.0 diesel.

The whole reason I did so was to be able to pull our RV better.

I don't know if I am doing something wrong, or if my truck is having problems.

Pulls fantastic around town and starting out.....the diesel is so much better. The issue is maintaining an average highway speed of 60 to 65 on a low to moderate hill. As I start going up the hill, speed decreases. Normally with a gas engine, I would step on the gas and the tranny would downshift and then I could control from there. This truck seems to not downshift as I step on the pedal very quickly and then as the speed decreases, the wrench icon comes on (which is the Electronic Throttle Control light) and I lose virtually all power. The engine continues to run, but seems to have no power. I will pull over. Turn the engine off and then immediately start it. The engine is fine and has normal power. I accelerate up the hill and it is fine overall until the next hill where this whole cycle repeats itself.

Any thoughts on what might be causing this? Is it my driving style? Is this normal for a diesel? Am I expecting to much to maintain that speed? My 5.3 liter gas chevy could maintain that speed on the same hills, be it at about 3800 rpm.....which is why I switched to the diesel.'

Overall, the truck is great other than I am getting only about 11 mpg even around town which I thought is very poor based on what everyone else says I should be getting with this engine. Could the mpg and this issue be related?

[JKH]

Are you engaging the Tow Mode? I have a '04 F250 with the 6.0 Powerstroke and I've not encountered that problem. I did have a problem with the Turbo whining, and they fixed it under warranty, for a carbon problem. Since the engine light is coming on, and I assume going off, you should get someone to read that. Your fuel milege is in the ballpark as I've been in the same range towing a 31' travel trailer. You should be getting 18 to 19 mpg in routine driving. If not that could be part of the problem.