Losing Throttle Pedal

[wolowic1]

Anyone have any ideas or have this problem? I have a 2001 Duramax with 58,000 babied miles. All the temps are good and fluids regularly changed. The cruise control works fine, but the electronic throttle pedal just stops working sometimes out of the blue. The truck will idle fine as well and I can actually drive the truck with just the cruise engaged and even accelerate using the cruise switch. When the throttle pedal goes out I have to stop the truck, turn the ignition on and off a couple times, and then I get my throttle pedal back. Some days it's fine and others it will do this once or twice. I've asked the dealer truck service manager and he's never heard anything like this. The only problem I've ever had with the truck is the injector pump changed in the first year or two under warranty. No service light comes on in the dash, but maybe I'll have them check it to see if they get an error code reading or not.

[cowboywildbill]

It might be a bad potentiometer. I hope I spelled that right. It is the mechanism that the pedal activates. It works sort of like a volume control does, if that makes sense.
I had a simular problem on a over the road tractor trailer. They replaced the pedal assembly and all was well.

[wolowic1]

Thanks for the input. That was a thought of mine and a couple friends mentioned the same. Just seemed strange that as long as I've viewed things here I have NEVER seen anyone post anything like this problem.
The dang dealer tells me "If you can get it to repeat then just bring the truck in when it does it". I was like how the hell am I going to do that when I have to get it to reset itself so I have throttle again and then all seems fine. Then even if I turn it off and call for a tow, chances are I start it again and all is well!!!!
Outside of this issue it's been an awesome truck from day 1.

[JohnC]

You can bet that if there is a problem with the APP severe enough to disable it, there are diagnostic codes being stored. Get the dealer to read them, and do it soon after the problem occurs as most codes will clear themselves after some number of trouble-free start cycles (50, I think).

[Kennedy]

APP modules seldom go bad. The 2001 had some ghosts in them. Some revolved around the air box and some were programing related.

Start here:

http://www.kennedydiesel.com/dmaxairintake.html

[wolowic1]

Thanks for the excellent input.
Damn thing did it again today and wasn't even warmed up.
Low and behold if the "service engine light" came on for the very first time since this problem started so I'd agree I should have some codes now.
Had to turn on and off the truck around 6 times before I got my throttle back, service light went off, and truck ran like nothing ever happened.
It's definitely irritating so not much choice except get her into the dealer to see what's going on.

[DmaxMaverick]

Get your hands on a scanner, or get to a dealer ASAP. There will be a code stored, even though the SES is off. It won't last forever, though. The code will reset after several start cycles. If you are a DIY'er, it will be in your best interest to buy a scanner capable of pulling and clearing codes on your vehicle. The Actron full function scanners are nice, and not too expensive. They also work on all OBDII vehicles.

[wolowic1]

Appointment with dealer in the morning.
I'm a DIY'er for sure, but I don't own a scanner. Maybe something I need to look into as you say for my own good going forward.
I'm comfortable with all the mechanical stuff, but honestly this electrical stuff is where it gets "dicey" for me and I lose my comfort level.
I'll let you guys know here what the dealer finds out.
I've also punched / drilled a bunch of extra holes in my air-box on the bottom which I read here about a long time ago. Filter is brand spanking new as well and the old one wasn't bad at all. Interesting pics of that side cut-out and then the foam put in place.

[wolowic1]

Don't have all the specifics yet in detail, but here's the short list.
The SES light and error code related to the front driver side battery leakiing at the bottom and getting onto the VCM. Must have been leaking awhile because I need a new battery tray as well. They get NO codes showing any pedal control issue so they think this is probably the cause of the issue. Changing out both batteries, the front tray, and the front battery cable. I haven't seen this yet so I'm assuming a very small continuous leak on the bottom side because I sure as hell couldn't see it from the top since I'm under the hood regularly. Batteries 5.5 years old so I can't complain there, but I've never had a battery crack and leak like this let alone a Delco. Total damages will be in the vicinity of $500. I'll post more details after I pick the truck up tomorrow.

[wolowic1]

What the dealer found in the end.
They originally got NO error code related to the pedal. Then the pedal went out after they thought it was battery related while they test drove it. At this point they pulled an error code. They said the throttle position sensor was shorted which was related to the power train control module having an internal short. So I have a new throttle pedal and the power train control module is on order. The PCM is covered under emissions warranty, but nothing else was covered.
Anyway at least it's fixed and I hope no one else has this same problem, but if you do maybe this will help find the issue.