Moderator if this is in the wrong place please move, this is my first post.

I have an 07.5 2500HD,CC,D/A, and am having a problem getting a message (clean exhaust filter) and the engine going into limp mode. This is what has hapened so far: drove 500+or- mi, drop trailer for 4 days. Drive around Big Bend, Hook up trailer for 60 mi drive, message clean exh filter(hearafter known as MESSAGE) and engine light, stop for two hours, MESSAGE gone engine light still on. Get to dest. unhook, drive around park 2-3 mi , 10 mph, light goes out. Drive back home no issues. Drive about 180 mi to dest. unhook for 8 days, highway driving 65-70 mph, hook up to go home and get about half way there MESSAGE, and limp mode, call dealer, ok to continue to drive to be able to drop trailer, continue in limp mode and drop trailer. Drive in limp mode 70 mi to dealer, regin performed. Go pick up trailer and head for home, MESSAGE and limp mode 70 mi, drop trailer and go to dealer, regin, change Oil and oil filter. Drive 414 mi to OK. Unhook and drive around 60 mi @ hwy speed. leave for home, drive about 150 mile an get MESSAGE decending south side of Arbuckle Mtns in OK, does not go into limp mode. Stop at dealer in Ardmore< OK. Cannot stop, he clears codes ????? and I head to TX. Get just north of Hillsborro have driven around 300 plus mi, get MESSAGE and engine goes into limp mode. Able to make it to dealer, leave vehicle they do a regin and Tech tells me there is nothing they can do other than the manual regin, and if i pull the trailer i will just have to unhook each time I get the MESSAGE and drive 30 or so miles so the veh can regin itself then rehook to my trailer and repeat this each time i get the MESSAGE while I am towing. This does not happen except when towing. I do not want to do modifications to engine or exhaust unless there is no other solution because i am still under warranty and when it is working I like the way the truck tows my trailer. Are there any GM Techs or others that may have encountered this problem. I am going to the dealer tomorrow to discuss this with them and decide if I need to call GM Hq.

I would find a new dealer or ask their permission for a dpf delete:D

Tiger8M,
What good is the truck if the problem only happens when towing, that would be a question for the dealer.
There is a tech here on DP "goodwrenchtech" he has help several.
One suggestion is to see about getting a code checker/clearer.
I suggest checking out Mac Tools part # ET50 it only costs about $70, I have pic`s of it in my garage. It is a very small tool then you would not have to limp all the way to a dealer, of course until the light comes on again. Then clear it again, but you still should get to a dealer.
Hopefully you can get the mystery solved and enjoy the truck, even when towing.

With all due respect DRC - I would be careful about clearing codes and THEN going to the dealer after you have cleared the codes... The code leave's a paper trail of what went wrong and why, when you clear it you could delete any history the tech has of finding out what went wrong - then you would have to make it fault all over again to get them to find something.

Just my opinion.

Discuss this with the service manager - ask to get the area gm rep involved and the gm tech line - and then call gm if there is no help or you get blown off. Ask for a loaner/rental truck while yours is in shop. These trucks are towing machines and this is not normal or acceptable. I would suggest the dpf or sensors are not functioning correctly while towing to burn off the soot and because it does work with a manual regen means nothing. Time for them to start looking at ecu updates and hard parts. GM is more customer service oriented than ever and a call to thier help line will have results.

how big/heavy is the trailer?

With all due respect DRC - I would be careful about clearing codes and THEN going to the dealer after you have cleared the codes... The code leave's a paper trail of what went wrong and why, when you clear it you could delete any history the tech has of finding out what went wrong - then you would have to make it fault all over again to get them to find something.

Just my opinion.

What I ment was, if he is out in the middle of nowhere and on the side of the road,why be stranded and have to go thru the hassle Tiger8M went thru.
If the problem is still present it will show up either right away or usually within 70 miles, I`ve delt with that before on another vehicle.
I have had codes, two times, with limp mode both times, different codes and both ended up being just a strange computer glitch, per the tech.
I limped the truck to the dealer both times.
He`s the one that suggested getting the Mac Tools ET50, so I don`t have to go thru that again, and note the code #`s to tell them.
If the codes keeps coming up, then get to the dealer ASAP, don`t ignor them.
OnStar can tell you whats wrong but cannot help you anymore than to tell you to go to a dealer.
What is nifty about the ET50 is it gives you the code # and a short explaination of the issue and is very compact.
"I don`t leave home without it".

Damn, that little snap on is a pretty handy gadget!!
I have efilive for that purpose (among other things) and if you note the code I guess you would be alright sharing it w/ the dealer.
Waiting on tow trucks SUCKS!

Just so you guys know, heavy loads actually help the regen process. The theory behind the "message" was for guys who putt around town at less than 25 mph and never get on the highway. To complete a regen the motor must be under a constant load. 55 mph highway speeds are enough to complete the regen. Towing any kind of a camper at any speed will cut your regen time in half or better just because it gets the EGT's up that much quicker and higher.

OP,

Your DPF is malfunctioning and needs looked at by some one who knows what they are doing. My guess is that it's cracked and blocking exhaust flow which the ECM is interperting as a clogged DPF. Does your exhaust tip have any soot on it? If so that would indicate that the dpf is cracked and not catching the soot.

Just got back from the dealership, going to set up a meeting and probably take the truck in. For LMM GUY i checked the exhaust and to me it has minimal soot. For AMOLAVER the trailer is 30 ft with GVWR of 9800 lbs, but one tech told me that the weight should actually help it regen, probably more often that when not pulling. Thanks for all the information and I will repost here when everything is figured out and fixed. I will wait for now on any tuners or electronic overide devices, I'm afraid of messing up the warranty.

Just don't let them tell you some BS about unable to reproduce/can't find anything at this time. I've seen that a few times around here going camping over the last 2 seasons with LMM's. Dealer tells them a line, same story next trip. I'm just glad I ditched all the emission cr@p, warranty or not. Can't imagine driving around in Limp mode with a camper and wife/2 little kids. Good luck, hope they fix it, sounds like a sensor issue. Too bad you don't have a way to read how much the DPF is "clogged" up when this happens, need a tuner for that. Chris

The Edge Insight "its a gauge and monitor only, not a tuner" it reads dpf and regen along with a whole bunch of other interesting parameters to keep a eye on.
Plus, you can retrieve trouble codes and clear them, with no concerns on voiding your warranty for around $300.

The Edge Insight "its a gauge and monitor only, not a tuner" it reads dpf and regen along with a whole bunch of other interesting parameters to keep a eye on.
Plus, you can retrieve trouble codes and clear them, with no concerns on voiding your warranty for around $300.

X2 worth every penny. There are great deals out there on the Insight.

Just so you guys know, heavy loads actually help the regen process. The theory behind the "message" was for guys who putt around town at less than 25 mph and never get on the highway. To complete a regen the motor must be under a constant load. 55 mph highway speeds are enough to complete the regen. Towing any kind of a camper at any speed will cut your regen time in half or better just because it gets the EGT's up that much quicker and higher.

Its a double edged sword. Towing drives up EGTs, making passive regen more effective. BUT, you're burning a lot more fuel, generating a lot more soot.

OP,

Your DPF is malfunctioning and needs looked at by some one who knows what they are doing. My guess is that it's cracked and blocking exhaust flow which the ECM is interperting as a clogged DPF. Does your exhaust tip have any soot on it? If so that would indicate that the dpf is cracked and not catching the soot.

If exhaust flow is being blocked in any way inside the DPF or DOC, the computer probably doesn't know about it. It will make assumptions about the effectiveness of passive regen, and if those are not correct, the pressure drop across the DPF will rise, triggering the DIC message.

Bottom line - a shop needs to look at this. Its in warranty, and you need the problem documented and hopefully fixed. The problem is going to be getting the dealer to drop the DPF and actually examine it since GM likely won't authorize it as a warranty issue. Chicken or egg problem...

ahm

Emissions system function is all about warranty.

OK, here is the up-date. Picked up the truck today, not fixed but waiting for parts. What I was told, a valve on or in front of the DPF is throwing some misc codes, which they say does not make it bad but they are replacing it, are we talking about the MAF here? The hose which goes to this was kinked. That will be rerouted so it will not kink again. They found all this out after they hooked the truck computer up to the internet and talked with a Tech. in MI. I have read several post on here about guages added to monitor boost, turbo temp, etc. What are the basic guages that would be good to add and what would they tell me, also would the edge insight that D R C suggested monitor these functions. If it did I think It might be a good addition. I will update this thread after I have a chance to tow the trailer which I hope to leave for Colorado and New Mexico (for cooler weather) the first of August, and thanks for all the advise so far.

etc. What are the basic guages that would be good to add and what would they tell me, also would the edge insight that D R C suggested monitor these functions. If it did I think It might be a good addition.
I suggest getting on www.edgeproducts.com (http://www.edgeproducts.com) go to the search and type in part # 83400 (quickerto find)this is the Edge Insight click on the manual and have fun reading everything it can monitor. It is pretty simple to install I bought the dash pod Edge sells and it just plugs into the OBD II port and "BAM" you have gauges. The only one you won`t have is EGT`s until you drill and tap into the pass side manifold.
Or to make it easier not $ wise would be to get the BD manifold for the drivers side it already has a port for a thermocouple/probe.

Doesn't do boost does it?

Yes it does read boost.
Read my post #17 again and get all the info one could ever want.