I have an '02 GMC 2500, 4x4 Duramax diesel. The check engine light comes on when in towing up-hill. Anyways, after un-hooking trailer and starting truck up later, the light goes off. Doesn't come back on again until towing up the hill. Called dealership and they want $300- just to hook it up to the diagnostic machine! Is this crazy or is that what people are paying for this!??  I am the second owner of this truck and had the Glow plugs all replaced and all the fluids changed. Fuel injectors are original as far as I know. There is no white smoke coming out of tail pipe when I start it and no "pinging" sounds coming from the engine. (Which is what I was told  would happen if it was an injector) It does however shoot out black smoke when I "get on it" (passing gear or up-hill) I just had the fuel filter changed and the black smoke is nowhere near as bad as it was before.(again..black smoke only in passing gear)A friend hooked it up to their "diagnosis machine" and it read a 1093 code which is "fuel rail system". Any ideas what it could be? Could it possibly be just 1 injector or what? A friend of mine has an '05 that she had to have just 1 injector replaced. But..she said she could hear "pinging". And told me, " you will know when an injector goes".

Also, while in tow haul mode, tranny is not shifting until it gets to the 2.5 RPM. Is this normal? It sounds like it is not shifting when supposed to. This is between the speeds of 30-50 MPH that it does this. Only the up-shift though. The down-shift is fine. And this is ONLY in tow haul mode that this is happening.

Black smoke on a diesel is just unburnt fuel being exhausted. That is why it is so common to see on Tuned engines where the injectors are turned up to higher levels.  The newer the engine the better the computer and injectors are at giving the exact amount of required fuel and not injected excess that turns up as black smoke.  Couple that with the Diesel Particulate Filters that were installed on all diesels after 2008 and you see very little black smoke on modern diesel engines. A bad inector can cause black smoke, because it is feeding too much fuel, but it is not the only cause of black smoke.

Tow/Haul, will cause the transmission to hold gear longer,. Keeping your engine in higher RPM for the extra power needed while towing.  So yes it is expected to see your tranny not shift at lower rpms like you would when your truck is empty.

If you know the DTC Code, Just call your service advisor and ask what causes it and what the estimated repair is. I have not had any check engine lights in two years since I bought my 2011 F350, But I had called several times on previous trucks and found the service advisor very helpful in telling me what the code ment and what the probable repair would be. It's part of developing a relationship with your service advisor. On several cases, I just came in and bought the parts and did the repair myself. No hard feelings with the advisor for telling me what the code was and how to fix it.

As far as paying $300 to hook up and read the code. You can buy several products that will read the code for you for that price. I use the Edge Insight on my truck (they sell for about $300). Acts as an extra guage most of the time, displaying oil and transmission temps.  But if I ever see the check engine light it will display the codes and even clear a code if I need it cleared. When I had a HPOP failure on my 2006 6.0L engine, Truck was dead, Would not start. Called my service advisor and gave him the code that the Edge Insight had retrieved. He told me what the problem was and suggested I clear the code and start the truck and drive it in for repairs.  I cleared the code, Truck then started, I was able to take my trailer home and then drop the truck off at the dealership for repairs, A whole lot better ending that having a tow truck come get me and worrying about how to get my trailer home.

AZgrulla,

 Thanks, I will try the dieselplace forums.

 Did your truck make any sounds that you could identify with the turbo solenoid? I do hear every once in a while...usually when the truck is cold, a whining sound? Like the radiator fan or a blower of some kind is coming on and then goes off. And I don't think it is the radiator fan either...it's just what it sounds like though. It doesn't do this all the time though but it is usually when I first start the truck up and then drive off.

call a different dealer.

I used to live less than a mile from a chevy dealer but their service is about what you are describing.  I called the GM dealer 30miles away and they are always better

Code 1093 from what I can see is: P1093: Fuel pressure low during power enhancement

I got that from here: http://www.duramaxforum.com/forum/911-problems-forum/1164-check-engine-light-dtc-1093-a.html 

Hope it helps.

Thanks Jeeppir. That is what I was afraid of, and of course it is no longer under warranty too right? It has only 84k on it. Ughhh. Well, it just sits now cause I don't have the money to get it fixed.

I don't have any smoke or smell of oil in the diesel though. At least not yet? Or is it diesel in the oil? Just had a friend change out the fuel filter and there is black something on the old filter. He tore into the old one to see if he could find pieces of metal or what not. He doesn't think it is oil though(on the filter)What else might it be?

The engine will actually warm up faster if you just drive.  No hard acceleration, no racing, just drive.

On mine, I can have the engine coolant warmer with 1 minutes of driving than I can with 10 minutes of idling. So start the engine, let it idle long enough to get the oil pumping and circulating and then drive. By getting a little turbo boost going, Your combustion temps will climb dramatically which will heat the engine block much faster, The coolant is working at cooling the block and you will see your coolant temps climb much faster.

Diesel engines produce soot.  The oil that you use in a diesel engine is designed to carry a high load of soot in suspension and still provide lubrication.  That is why you don't use the same kind of oil that you would use in a gas engine. Make sure the oil you use is designated for a diesel engine. New oil goes into the engine with a golden color and will turn BLACK very quickly.  After 5000 miles everything in the oil filter will be black from the soot carried in the oil.

Equinetransport,

I have an '06 2-horse all aluminum Classic trailer ( gooseneck)It weighs with nothing in it 4400. So, nothing for my truck to pull with 1 horse and my camping gear. I'm not losing power up-hills yet..well it is slowing down a little but if I press the pedal it goes. Anyways, No bad sounds...just that annoying "service engine soon" light comes on, on the hills. These are slight hills, nothing major. No ruff engine ride yet anyways.

Most of the devices that will retrieve and display the code will also delete and reset the code.

The fuel filter just got changed a week ago. Yes, it was an AC Delco fuel filter. I had to go to the dealership to get it since no one around here sells them. Have fueled up 1 since then but this has been going on for a month now? Maybe more. Had the oil changed at the same time. It is running much better and def can tell the difference since the fuel filter got changed out. Almost thinking it didn't get changed out the last time even though I asked for it to be done while the oil was getting done. Cause it had to have only been 5k in-between since I had it changed out before this last time.

Paul... will do all that you suggested. Thanks! Will let you know.

Good information given by everyone. I have a 2002 2500hd also and have an injector going bad white smoke at idle, that conversation for another time.

 This post reminded me of one I read about a 5th wheel camper with similar problem and only occured with trailer hooked up. Had to dealer several times - long story short there are some flexible sections of fuel line on the supply side that can colapse and only cause problems under high demand for extended time (pulling hills with trailer).

These trucks don't have any kind of supply pump in the tank to push fuel to the front. The cp3 unit pulls all the fuel to the front, therefore any restriction cause a drop in rail presure.

Someone mentioned the airdog system which is a pump and filter setup that helps push fuel to the front and would probably fix your problem even if lines are marginal. These add on pumps usually push 8-12 psi of fuel to the cp3 unit and makes its job much easier.

The duramax forum has a lot of information also.

ok...I took truck back to the dealership cause I hauled  the horse to the vet the other day. This time my truck had no power going up the hill and it was riding rougher than usual and louder. Dealership called and said they want to change out the injectors...that they are pretty sure that is what it is. Ok- you ready for this.......$5200-!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

First of all, it was a diesel technician and not a mechanic! There is a difference right??????  So I asked what injectors were bad. They couldn't tell me!! Well, that would take a deeper look at everything he tells me. So now, I have paid $300- for the diagnostic and the truth of it is....they don't even know if it is the injectors!!!!!!! He said they did a pressure test on it and it was showing a return of 16#? and it should be at around 50-60#??? Still, it starts up no problem and there is no white smoke coming out the tail pipe. Then the engine light goes off as soon as I turn truck off and disconnect the trailer and re-start the engine later. So, I told them to put it back together that I will be picking it up the next day. So, now I am looking for a good diesel mechanic other than the dealership to look at it.

Hi Paul,

Yes the tranny was just flushed recently this year. I had all the fluids flushed and changed out by the dealership at $1000-

I am picking the truck up from the dealership today and am looking for a local diesel mechanic as we speak.

equinetransport,

That is what I will do when I wake up.....call around for a diesel mechanic. Had the local horsemans meeting last night. I asked around who everyone uses and got a couple recommendations so will go from there. Thanks all!

Paul,

could this wiring be under or near either of the batteries? I just had to change out the batteries even though they were only 3 years old because they were bad batteries (bigfoot- from Big O' Tires) They were leaking all over the place. both of them.

Snoweary,

 I asked the dealership to let me know what injector is bad because I cannot afford to do them all right now. They could not tell me. So, this says to me that they didn't do all the necessary tests and then they told me to get them all done at the same time so that I wouldn't have any go bad again any time soon. Well my thing is I can afford to get them all fixed next year but not this year as I have spent all my savings already this year trying to keep on top of everything. First they charged me $130 for the diagnostic and then they call me back and say that they are going to need to do further research to see more and that that was going to be $290- well I have the truck back and they aren't telling me any more than they did when the diagnostic charge was at only $130- This is what pisses me off. They didn't DO anything after the first "look" at everything. And they charged me the $290-  Just really frustrated now.

snoweary,

yeah......I wanted to get a fridge and a cowboy shower installed in the trailer this year but it ain't gonna happen this year. Ughhhh

Paul,

regarding the battery cables. I did not even see this post until today the 3rd of October. I don't know how I missed this but thanks! Yes.... you rock!

Paul,

 That's what i need to ask this guy about.
Thanks for the reminder.

UPDATE:

 Gm has agreed to pay 50% of the truck repair!!!!! I had such an aweful time trying to contact GM customer support.( They do not answer the phones) So, yesterday I called the dealership to tell them of my frustration that I could not get anyone to answer the phones at CS. ( I had been calling for a week) So, I get a call today from one of the guys at the dealership that works in the service dept., stating that he called the GM Customer support( they have a direct line to them he tells me) and got GM to agree to cover 50% of the costs of replacing my fuel injectors.

So, this means I am paying $2438  instead of the $4800 to do the job. Much much better. Whewww!