this is on an 03 2500hd 6ltr. This just started about a month ago I left my driveway and didnt even get 50yards down my road and the reduced engine power came on, this was first thing in the morning, the truck had been sitting for over 24 hours. since it wouldnt go faster then a few miles an hour i pulled it to the side of the road and shut it off, and got out the owners manual. The manual said that this comes on if it is over heated, my gauge wasnt even rising yet. I started it back up and it was ok the warning was gone. I drove it for about two weeks then the same thing happened. today it did it again, first thing in the morning, shut it off, wait 20 seconds, start it and it is fine, I do have to disconnect the battery to reset the ses light.I checked the dex cool and it looks fine I havent lost any and I can drive the truck and it never gets over the normal range(210). any ideas, the truck has 106,000 miles and never had a problem with it. this is just bothering me.

thanks

isie

Isn't the reduced power mode also invoked if your truck thinks you've lost a cylinder?

It's probably worth it to not reset the ses but take it somewhere that can scan the codes to see what the engine/pcm THINKS is happening.

i have now spent $2000 trying to fix this problem, as it gets progressively worse. latest fix, throttle body. will let you know

did they replace the connector and pigtail for the throttle body electrical plug? there is a common problem with one of the yellow wires breaking pretty close to the plug.

I probably shouldnt say this but I put a new throttle body on and so far so good. The old one had a crack on the backside, that I am hoping was letting moisture build up and causing the problem.Also the new throttle body does not have to be recalibrated whith a tech 2.everything that i read and the dealerships all say it does. My father in laws neighbor is a GM mechanic and he got the part for me and I asked him about the tech 2 and he said no, they tell you that so that you dont attempt it. so i will keep my fingers crossed.I also have an elmscan 5 and laptop, that is what pointed me to the throttle actuator control, I also tried all the broken wires and loose ground. just looked at when I first posted this, should update it. the problem got worse shorter periods between when it would happen. I finnally gave up after trying everything suggested and took it to a 2 dealers, they could never find anything wrong. they said they didnt want to replace the tac because there was nothing wrong with it. I finnally did it and so far so good. sorry for the long rambling post. If you have any questions email me I fought with this for awhile and might have a suggestion. I also didnt spend $2000 only about $250.