Part I
Now that the 2005 LLY Surge Update (re-flash) from GM has about a year or so under its belt, how is it doing? Is anybody starting to experience it again, or did GM give it a permanent cure? A friend of mine said that his DMax/Allison surge is starting to come back. He got the re-flash earlier this year.
I'm just wondering if the re-flash was for a programming flaw, or just a band-aid for something mechanical?

Part II
Any ZF guys get rid of the surge? If so, what was the fix?

Story time
I got caught up in some accident traffic last tues. morning. I could not move with traffic doing 10 to 20mph without it bucking real bad. It did not matter what gear I was in.
What I know is, it only does it with about (for a lack of a better description) 2 to 7% throttle. I can also feel the surge when doing 55mph, going down hill, with the same throttle %. Now, I did notice something, I did my fuel filter change (filter had about 13,000mi on it), the surge went away - for just one day, and then came right back the very next day. I though Ah Ha. When I took the old filter off, the fuel level in the filter was low. So for the next two days I kept the filter primed all the way to the top. Did not help. Fuel additives do not help. I have had this problem since about 6k miles on the truck. I have about 37k on it now.
The Dealer said, "It's just the nature of the Diesel engine," I call BS on that one. So my dealer is no help to me at all. :mad:

Any comments...besides go to another dealer, because form what I hear, all the GM Service Departments around here suck when it comes to DIESEL knowledge. (They are good with Gas vehicles though.)

Any comments on Part I or Part II of this thread?

jc

I got the re-flash and it was really good for a while, but the surge came back after a month or so. Maybe it's not as bad as before, but it's definately back. By the way... I have the ZF6.

My son got the re-flash and the tech said there was a restriction in fuel line. Changed the fuel filter. Surge is still there. He was to make another appointment. He also has the 04.5 w/ZF6.

There is one surge that is fixed by the re-flash - this is a light surge with a light throttle application at 1100 rpm, etc. There is another surge that is experienced when you have a sticky fuel pressure regulation. The latter one can be alleviated by using a good additive to clean and lubricate - my choice is stanadyne lubricity formula.

jeff

I had the reflash done on my 2005 lly. It had a slight surge at parking lot speeds, so I thought I'd get it reflashed while still under warranty. Now it still has the surge plus it has a lope at idle. I had it back a couple of times, they said it took the reflash and don,t seem to know where to go from here. It does'nt always do it though, sometimes it idles smooth. Any suggestions? Completely stock, 35000 miles.

I had the reflash and it never did cure my surge

When I had mine re-flashed for the surge it made it worse. Any time you try to feather the throttle it jumps. It gets pretty old. My wife absolutely hates it.

I had the reflash done in May or June and have not had a problem since. I have a friend that did not have the reflash done and his surge went away on it's own. Gremlins is my guess.

what is this parking lot surge

after the reflash mine was good for a few days but then it came back, been living with it ever since...

It's nice(?) to have company. I don't think that the reflash did anything to my surge.

what is this parking lot surge

YOU'LL KNOW IT IF IT HAPPENS TO YOU. JUST OFF IDLE THE TRUCK WANTS TO BUCK OUT FROM UNDER YOU. SCARED THE CRAP OUTA ME 1ST TIME!

I had my '05 reflashed for it but traded it in about 5 k later and had not seen it completely go away but it was quite a bit better.

I had the surge on my 2004 lly and did not have any codes. At any stop it would surge forward and smoke and seem to somewhat go away at first when the engine got to normal operating temp. Then it progressively got worse, so I took it an had the computer scanned. It showed no codes. Then I called a few dealers before talking to the right mechanic who knew what I was talking about. It turned out to be 2 injectors were bad and they reflashed the computer at the same time. About 14k mi later and no problems.:D

Mine did it bad, but after the flash it never did it again, that was 1 year ago.

Here's a link with the flash part #'s that took care of mine.
http://dieselplace.com/forum/showthread.php?t=57139

I'm Thankful for all the feedback.

KEEP THE COMMENTS COMMING IN.

I was thinking of replacing the Fuel Pressure Valve till I saw HOW MUCH THEY COST!!! :eek: That was the most promising fix I have read about here on the forums for a while, but I am seeing new "fixes" from you all.
This is just bugging the h*ll out of me. Now that I am driving slowly on snow/ice packed hilly roads, It's not a drive, but a F'n adventure.
I am thinking of just going ahead and go dealer hopping and try to find a helpful Service Mgr/Tech. I just do not feel like paying $100 (I'm past the 36,000mi mark) for a fix that will come back in a day or 6 months from now. I'm looking for things for them to check.

--> Have any of you GM shop techs found a fix, or have anything to add? <--

Thanks
jc

ps: I'm interested in the ZF6 guys' comments on this seeing there is not a re-flash fix for them yet, if ever. I'm surprised they/we aren't complaining about this more.

Had mine done in october when it was in to have codes for the EGR cleared. The flash seemed to me to soften the throttle responce in 1st gear at off idle to maybe 1200 rpms. It made mine better and has stayed that way ever since. Just guessing but I would say it is just programming to adjust the way the throttle responded to pedal input. The spring tention on the pedal is very light and on my, a truck bumpy driveway caused my foot to move the pedal more than needed and in turn cause the motor to respond so the fix is to change that responce to the input.

i dont know if its the same problem from the reflash but at idle mine is like a car with a radical cam in it sometimes real bad and others kinda not so bad but can feel it at the lights. fuel filter is new and air cleaner is cleaned. not sure what it is but it suks!!!!

Had mine reflash inFeb. 05. Real bad parking lot surge, your head would be bobbing, wife hated it . Refash really helped, but now the pedal is super sensitive. When going slow or through a dip or bumps it will jerk an surge. If you let off or step on it , it smooth out just fine. Pain when driving rocky desert roads. Maybe Boost, Timing, or Fuel ?

Mine had the surge. Re-flashing did nothing. They then found the terminal on the fuel pressure Regulator Solinoid broken off or corroded off (can't remember) and that cured it. Part # 22724772. $ 13.17 at http://www.gmpartsdirect.com/

Ours hasn't done this yet, however my CTD 'surges' at highway speed during hot weather. With the cruise set at 65, it has a lunge every 30 or 40 seconds.

My son's '04.5 ZF6 has a bad surge. 67K miles. Took to dealer. Re-flash didn't help - $80, new fuel filter didn't help, wiring harness didn't help $65 + labor, now they think it is the fuel pressure regulator (FPR) - $800. The FPR is what this site said was the problem to begin with and he told them. Now to beat it all they are saying these repairs are not covered under the 100K warranty (say they are maintenance items). Contacted GM (1-800) and they supposedly negotiated with dealer for GM to pay for the parts. Just what is covered in the 100K engine warranty? No wonder GM's stock is in the toilet and may go under if/when a better product can be found.