Hi all
I've been following some of the forums writings on recalls pertaining to GMC reflashing the Duramax.
My '08 Duramax was recalled and reflashed for an apparent "non starting issue" that "could" crop up. Soon after the reflash I went to the mountains.
I just got back from that 1100 mile trip from Jacksonville Florida to the North Carolina mountains. I pulled an enclosed trailer up weighing around 5000 pounds. My Hypertech was one Stage 1 going up and Stage 3 coming home. On the whole trip my truck only regenerated once and for a shorter time. My mileage on the way home (trailer-less) at 75 mph was a pump checked 20 mpg, 14 mpg going up at 65 mph. I was happily surprised.
I was wondering if anyone knew if possibly GMC was also correcting a regeneration problem?
Any info would be great. My service tech...at GMC didn't even know the new trucks regenerated. That's funny! Way to teach those guys.
Franklin

Hi all
My service tech...at GMC didn't even know the new trucks regenerated. That's funny! Way to teach those guys.
Franklin
I think i'd fine another service tech...

Hmm, I am not seeing the samething. Regens still every tank and I am in the middle of a 5000 mile trip.

I had my 08 gmc 3800 miles reprogrammed and i asked the tech if he could tell me how many times it had regenerated. he said he could not and maybe it had not because i have never seen a regen mode on the dic. I know it did once @ 350 miles and once about 750 miles. I could see the mileage drop and smell the heat. Does a light come on in regen. mode? john

I had my 08 gmc 3800 miles reprogrammed and i asked the tech if he could tell me how many times it had regenerated. he said he could not and maybe it had not because i have never seen a regen mode on the dic. I know it did once @ 350 miles and once about 750 miles. I could see the mileage drop and smell the heat. Does a light come on in regen. mode? john
No a light will not come on. Yes the tech could have told you if he knew what he was doing. The ecm does record this data and can be seen with the tech 2. I know I have done it several times for customers.

The only way to tell if your truck is in regen is a drop in mileage and possibly a funny smell if stop and get out while its going on. You also might notice the exhaust is really hot if you walk by it.

If you buy a monitor like the Edge Insight, it will tell you when your truck goes into regen. It would have been nice if GM had added that feature to what the DIC can tell you.

John K

The only way to tell if your truck is in regen is a drop in mileage and possibly a funny smell if stop and get out while its going on. You also might notice the exhaust is really hot if you walk by it.

If you buy a monitor like the Edge Insight, it will tell you when your truck goes into regen. It would have been nice if GM had added that feature to what the DIC can tell you.

John K

I don't think the majority of the truck owners even know that they bought a truck that has mandated emission stuff on them, nor do they care. We on this site are the minority of the truck owners out there. In 2003 the DIC had many more features that I used, like the business trip, etc. A majority of the owners complained it was too busy for them. So GM took alot of those features off. If they would of put a message stating the truck was regenerating, it would just confuse the majority - something else to distract them.

Another way you can tell your in regen is when your tailpipe start smoking. Mine just started doing it recently (past month). I'm not sure if it still does it.

Without a pyro you must look at the tach and listen to the engine. With my LMM, there was never a time I didn't know it was in regen. It will normally idle close to 500-600rpm and when it's in regen that will bump to 750-800rpm. (Not sure on exact numbers while sitting at the pc) Basically, I could hear it everytime it did it and if the needle was closer to the tick at 1000rpm than 500rpm it was in regen at idle, so the secret formula is: Close to 500rpm=normal Close to 1000rpm=regen

something I noticed about my flash is now my oil monitor is a 59% before the flash it was 71%? could they have changed the interval for the OCM?

something I noticed about my flash is now my oil monitor is a 59% before the flash it was 71%? could they have changed the interval for the OCM?


I bet the sudden drop was part of the unreliable, "gayness" of the OCM.:D I wouldn't be worried, I've noticed large drops too. Just be sure to check your mileage instead of trusting that thing. Does anyone know what that thing is actually monitoring?

I bet the sudden drop was part of the unreliable, "gayness" of the OCM.:D I wouldn't be worried, I've noticed large drops too. Just be sure to check your mileage instead of trusting that thing. Does anyone know what that thing is actually monitoring?

Mileage driven, and average speed. If the average speed is higher, it lets you go longer distances between oil changes. If average speed is lower, (indicative of city driving) it shortens the intervals for oil change. There is no "probe" that is sampling the oil in the oil pan as some people think, it is simply a mathematical calculation performed by the DIC.

Mileage driven, and average speed. If the average speed is higher, it lets you go longer distances between oil changes. If average speed is lower, (indicative of city driving) it shortens the intervals for oil change. There is no "probe" that is sampling the oil in the oil pan as some people think, it is simply a mathematical calculation performed by the DIC.

Thanks. You learn something new everyday. :D Maybe the dealer had the truck idling in the lot after performing the ecm update (and moving it around the lot) and it gave him the sudden 12% drop?

in my 2007.5 lmm, it would regen and on the dic it would say it was doing it and see owners manaul. (would get calls from people who barrowed it and it would say that. they would get worried) anyway my 2008 doesnt say that message on the dic. i was wondering if it has done it yet? 2200miles or so and always looking for the signs for the regen? guess il run it to the dealer one day to see. kinda waiting for a regen and then i can put my ppe and 5inch on her and let it breath and be a diesel.

your 2007.5 was clogging the DPF is why you were getting that message. I have a 2007.5 and mine has never showed it was regenerating on the DIC. The message you describe is a warning you need to run your truck at 30 MPH at least for 20 minutes or so to try and clear the DPF.

in my 2007.5 lmm, it would regen and on the dic it would say it was doing it and see owners manaul. (would get calls from people who barrowed it and it would say that. they would get worried) anyway my 2008 doesnt say that message on the dic. i was wondering if it has done it yet? 2200miles or so and always looking for the signs for the regen? guess il run it to the dealer one day to see. kinda waiting for a regen and then i can put my ppe and 5inch on her and let it breath and be a diesel.

Unfortunately, none of them will give you a DIC msg that you are in regen. You have regened many times if you have 2200 miles on it. You probably go into regen on average of once per tank.