I have this frustrating problem now that when towing a trailer up a steep hill for awhile the truck will not down shift and do what it is supposed to do. The truck will literally start up the hill at 2500 rpms then drop all the way down to 15/1800 and speed drops and the truck just lugs. When I put the pedal to the floor nothing happens, the engine doesn't work harder or anything. Now the engine has a hypertech programmer on stage 2 and my idea is that it is going into protection mode and de-fueling. I don;t have a pyro gauge but i know EGT's sky rocket when lugging the engine like that. However, when the tranny DOES downshift, it go into 2nd i think, rev out to 3000 rpm then shift up to 3rd and 2500 rpms and the truck pulls like a bat outta hell like its supposed to. The truck has a suncoast tranny and billit TQ but i know the tranny is fine. Now will a DP-tuner fix this stupid problem, is it a problem at all? BTW, if I do the DP tuner, guages will also be put on.

 

You definately have an issue in my eyes. Here's a bump for ya.

 

well theres something wrong there... it should down shift on its own, but i am not a auto tranny guy so i will just give you a bump

 

thanks for the bump guys but man is it frustrating to have the power that could pull a house but barely creep up a hill. I will also add that the truck shifts normal if I am cruising 70 at the start of the hill and hammer it all the way up. its only when towing at the normal speed, 60 then trying to get the truck to maintain that speed going up hill.

 

I would think that it should down shift before that range in the RPM. I have only pulled a few trailers with my truck, but it has never done that.

 

Until you can get this problem resolved I suggest you hit the cancel OD button as soon as the truck starts to slow down on a grade. This will help keep your EGTs in check.

If you're interested in a DP Tuner give them a call and explain your issues.

 

Actually the OD off drive won't make a difference, the tranny just stays in 4th. Im thinking its the crappy hypertech defueling when i senses high boost or something along those lines. Correct me if that is way off

 

Does "off" light up when you cancel OD?

I have zero experience with Hypertech.

 

yep off is lit up, sadly it only happens while towing up a steep hill and I dont have any hills within 60 miles so i can't just test things. I also forgot that the truck seems to be sucking the fuel like crazy, 9 mpg lately.

 

It probly is defueling when you boost above 22psi but it's not the programmer it's your PCM. And there is definatley something wrong if you hit the od button and nothing happens. Does the od off light come on? May be the wires are chaffed under the column if it doesn't come on. So to answer your question about the dp tuner fixing this problem, I don't think so. You should try towing your load without the programmer in and see if you tranny acts right. Then you'll know a little better where to look for your problems.

 

I would definetely try it with out the programmer but in stock mode, the tranny shifts unbearably hard. to the point it feels like the engine is going to drop out from under the hood. A built tranny does not like the stock tune at all. When I say nothing happens with OD off, i mean the truck isn't in Od to begin with so it doesn't shift down. If I am cruising 70 in OD and hit the button then it does shift out.


Also kind of off topic but, will a DP tuner in 80hp tow mode change the shift points so instead of dropping from 4th to 2nd then 3rd to just 4th to 3rd? This is when the truck is running GOOD haha. It seems that 3rd will pull hills at 70+ but I just can't seem to get there smoothly or even get in that gear at all. Damn automatic, It would be nice to have paddle shifters with a sport mode.

 

I have the same problem. I'm running a stock trans and a hypertech (only for a little while longer) and she just won't downshift until it's ridiculous. Then it kicks all the way to 2nd, the RPM's skyrocket and then it goes to 3rd. There's one hill here in town that does it even when I'm not towing. I'm tempted to put the stock tune back on and go climb that hill.

 

but then in 3rd it pulls like crazy right! It has to be the programmer then. It seems that the ony problem is shifting and hypertech does nothing with shifting so we are up-ing the power on the motor and not changing the tranny to deal with the extra power. Now the whole thing is hoping that this theory is correct and the DP tuner will fix it.

 

Wow that's scary, get rid of that tuner. I'd say even stock is better than what that tuner is doing to the truck. I can only imagine the egt and trans temp towing in that scenario.

 

Well now that two of you with hypertec are both having the same trouble I may have pointed my finger in the wrong direction. Definitely pull the program out and see how the tranney acts. Of course it will be sluggish compared to what your use to but it will tell us the trans is shifting like it should. Another thing you could try is taking in that hill with the od off then it will be in third already. Just a thought!