Help! Duramax wrong codes

Help! Duramax wrong codes. <HR style="COLOR: #d1d1e1" SIZE=1><!-- / icon and title --><!-- message -->Can anyone give me the phone number to Chevrolet's Medium Duty Truck tech. assistance? And just how does GM fix their "limp mode" explanation?

Got a 2004 Chevy Kodiak 4500 w/ Duramax LLY and Allison trans. Driver been down 4 times in 500 miles since 11/23/'04 and now down in Tucumcari, NM.

The truck's RPM drops down to 2200 and won't pull. Can't get better than that and ends up on the tow truck hook. No one can diagnose why?

Got towed from 1st dealer in Tucson - they diagnosed bad turbo. had to order in after Thanskgiving. Turned driver loose, he made it some 60 miles to Benson, AZ. Dealer there diagnosed bad fuel filter and turned him loose after replacing that. He made it to Albuquerque. Dealer there diagnosed another fuel filter problem changed it but wanted to run all codes for the truck but GM would not approve. My driver made it to Tucumcari, NM and down again.

I've had it with explaining over and over each time we have to get towed. GM customer service is anything but. I want a particular clown at tech. assistance to explain to me just why he w/n approve a more thorough check on my vehicle. It's me that's losing hundreds of $$ per day, losing customers and trying not to lose a good driver that couldn't even enjoy his holiday with his family.

If they're getting codes saying all is well and it isn't - change the bloody computer and let me roll. I've had an unnecessary turbo. change, and 2 fuel filter changes (my expense as none warranty - the fuel filters, not the turbo.), for nothing.

Would appreciate getting that number, guys.

Thanks!

Frank Bagnall
tlcmarine@comcast.net
cell: 469-576-9738
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I would start by getting it to a dealer that can properly diagnose the issue. Sounds like a lot of guess work . Look in the owners manual for the customer assistance line.

Kinda reminds me when I left my high idle switch on and tried to drive. Would get to about 2200 rpm and then be a dog. Just a thought.....

4x4hunter1,

dmaxalliTech's advise cannot be emphasized enough. I will not have GM service or anyone tow me to John Doe's Pontiac/GMD/Huydai/etc. at any cost....

They don't have anyone qualified or capable of doing any work on the GM MDT's, from service manager down, and will cost you more in heartache and out of pocket business expense than the cost of towing you 20 or more miles further to a GM Commercial dealer that do not work on pick-up trucks, cars, lawn tractors, chain saws, or battery operated dildoes (about all they are good for).

When your business (income) rely on your truck being on the road and working, you can't afford to skimp on service. GM Commerical dealers send their techs to training for these larger trucks. They are aware and informed about aftermarket upfits (which car dealers seldom see, and are certainly not competent to deal with), which could affect the performance of your truck, and can often be the cause of problems, especially those that are "not in the book".

Going to John's Pontiac & etc. will cost you big $$$ just to save a few dimes. So beware and fore-warned. When your truck is your income, down-time is the same as unemployment, except when your paying drivers to sit on their hands in a shop instead of working, which is even worse.

I agree with the others about finding a competent dealer. It sounds like they gave you a story. GM does not pre-authorize work. If there are codes they will pay to fix it.

How big is the load he is pulling? Since you picked out 2200 that is right were the code says to stop the motor if it's in a default mode. The typical cause of this is the transmission slipping. The driver can pull over and stop the vehicle and shut off for about 1 minute then start out again. If the trans does not slip then all will go back to normal and it sounds like this is what's happening to your rig. Maybe this help will get him to home base so you can find a good dealer that knows what they are doing.

Thanks for all the suggestions and some are very close to zeroing in to what just might be our problem.

I'm being told that my problem might be that the computer is thinking that we're using the PTO and limiting RPMs to 2000. Driver has to pull over and has no power to pull our transporter with a yacht on it.

This truck came in with the wrecker package, inclusive of a PTO. We never use the PTO feature and it's not powering anything. We don't push the PTO selector switch, either.

Unfortunately, most techs. live by the diagnostic codes and haven't a clue if they don't have any. If the vehicle isn't throwing codes while in the shop, they're scratching their asses, in bewilderment. Hence the unnecessary turbo. change and two fuel filter changes, all within 500 miles, along with being on the tow hook 4 times. Here's an example of why on-board computers and sensors suck.

Has anybody experienced this problem and what was the fix?

Thanks.
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if you think it may be PTO, you can hook up a tech2 and it will indicate whether the PTO is activated (at the moment) i case its a faulty wiring...

Diesel tech may be right too about the limp. once he shuts it down and restarts it does it act ok? how much does the load weigh?

The dealer in Moriarty, NM (Tillery Chevrolet) is a Medium Duty dealer. Their tech has a lot of experience on the Duramax/Allison combo. They are who I use when I am pulling my hair out with wierd problems - always come through. Trouble is, they are about 21/2 hilly hours to the West of you.

I bet it is a 1093 code low fuel rail pressure. Could be a bad sensor sensor. Or I could be totally off. It would explain why they were pointing to the fuel filter.

I assume you are stock with no power adders? A lot of us are seeing this problem when we start turning it up. No one knows why yet.

Next time it happens, be sure and have the tech give you the stored trouble codes and post them here.

my 01 duramax would shut down and only run up to 2200rpm, pull over shut it down for 10 sec. restart and would be fine for a period of time. found out low fuel pressure, due to high return rate of fuel from injectors, had to replace all injectors 3 weeks ago,runs just fine now.