I thought some might find it interesting that I was having some problems with my 2004 that included a mild bogging of the engine below 2000 RPM and extreme downshifting (up to 5000 rpm) of the transmission when on a very slight incline on cruise control. I had read on the forum that the cruise control problem was common so it was with not much faith that I went into the Coral Hummer dealership for a fix. I was told that the factory had come up with some new code that might help but not cure the problem. When I got back my truck I could immediately tell a difference. No downshift on slight inclines and only a smooth downshift on steep inclines as you would expect. Here is the kicker. My Highway mileage before the fix was a lucky 11.5, after the fix, 13.8 with more acceleration across the board. The only thing I can figure is the truck must have been running very rich from purchase. The new codes leaned it way out. Has anyone else had this fix done??

I thought some might find it interesting that I was having some problems with my 2004 that included a mild bogging of the engine below 2000 RPM and extreme downshifting (up to 5000 rpm) of the transmission when on a very slight incline on cruise control. I had read on the forum that the cruise control problem was common so it was with not much faith that I went into the Coral Hummer dealership for a fix. I was told that the factory had come up with some new code that might help but not cure the problem. When I got back my truck I could immediately tell a difference. No downshift on slight inclines and only a smooth downshift on steep inclines as you would expect. Here is the kicker. My Highway mileage before the fix was a lucky 11.5, after the fix, 13.8 with more acceleration across the board. The only thing I can figure is the truck must have been running very rich from purchase. The new codes leaned it way out. Has anyone else had this fix done??

I thought some might find it interesting that I was having some problems with my 2004 that included a mild bogging of the engine below 2000 RPM and extreme downshifting (up to 5000 rpm) of the transmission when on a very slight incline on cruise control. I had read on the forum that the cruise control problem was common so it was with not much faith that I went into the Coral Hummer dealership for a fix. I was told that the factory had come up with some new code that might help but not cure the problem. When I got back my truck I could immediately tell a difference. No downshift on slight inclines and only a smooth downshift on steep inclines as you would expect. Here is the kicker. My Highway mileage before the fix was a lucky 11.5, after the fix, 13.8 with more acceleration across the board. The only thing I can figure is the truck must have been running very rich from purchase. The new codes leaned it way out. Has anyone else had this fix done??

Looks promising. Did the dealer readily update the firmware or did it require some encouragement? Also do you know what the new code is called or have any other details?

I had my "updated programming" done a couple of months back -- dealer readily update (though if you don't request, they will not volunteer). Definitely worth the effort (though only for so long before you're hungry for more power ).

Is their a bulliten # for this update. My Hummer dealer knew nothing about this.

That's why I drive 45 minutes to get all service done at Cerritos Hummer -- speak with John or Mike (the "guru").

Btw, oltimers update: though I never bring it in just-detailed condition anymore, they now wash my H2...

I wouldn't mind knowing what to ask the dealer so I can find out if they can do it. Spill it Finally!

I dont know what it is called. I can tell you I got the work done at Coral Hummer in Pompano Beach Florida. They did keep my truck for about a week working on the problem. When I picked up they advised they had called the factory several times to find a solution. Eventually they downloaded the other programming. As I said, it really smoothed out the shifts on cruise control. And the mileage is holding steady. I agree with the statements about them needing a push to do it. I wonder if this is the factory doing their own performance tune like the proflash or predator. More power means more stress on the engine/trans during the warranty. Maybe it explains their hesitation?

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by frank6150:
I wouldn't mind knowing what to ask the dealer so I can find out if they can do it. Spill it Finally! <HR></BLOCKQUOTE>It really was called "updated programming" when I had it done (hence the quotation marks..)!!

Interesting... There must be a Technical Bullitin on this? Does this apply to a '03?

KLAUS, could you help with the Technical Bullitin number?

Thanks.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by H2Finally:
I had my "updated programming" done a couple of months back -- dealer readily update (though if you don't request, they will not volunteer). Definitely worth the effort (though only for so long before you're hungry for more power ). <HR></BLOCKQUOTE>H2F where did you get it done at.

luckily i am a gm tech and have access to all of gm's technical bulletins on si2000. i reprogrammed my pcm for every bulletin. if you want the bulletin# i will post it tomorrow as i am home now. i know the customer complaint is for a harsh downshift.so if you want the pcm programmed just tell the dealer you have a harsh downshift from 2nd to 1st gear and you know there is a reprogram for the concern.

I would like to have the bulletin number and details if possible, thanks.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Albie:
H2F where did you get it done at. <HR></BLOCKQUOTE>Cerritos Hummer (actually GM Service). You have to get it while getting work done, like oil change. Speak with John. Ask for Mike if you have tough tech problems. Yes, I am now a covert and thinks that Cerritos Hummer Svc is the best thing for SoCal Hummer owners!

the technical service bulletin#03-07-30-028
if someone whants too tell me how to scan and post it i will.

<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by H2Finally:
<BLOCKQUOTE class="ip-ubbcode-quote"><font size="-1">quote:</font><HR>Originally posted by Albie:
H2F where did you get it done at. <HR></BLOCKQUOTE>Cerritos Hummer (actually GM Service). You have to get it while getting work done, like oil change. Speak with John. Ask for Mike if you have tough tech problems. Yes, I am now a covert and thinks that Cerritos Hummer Svc is the best thing for SoCal Hummer owners! <HR></BLOCKQUOTE>
Yeah pasadena Hummer blows........ Thanks

H2F...was the reprogramming annotated on the repair order? I had Cerritos change out a leaking shock the other day....they indeed do good fast work..i and out in 6 hours! The next oil change i would like to get the reprogramming done.....

Thanks....

Attila, I can't remember (been a while). I believe there are more recent updates available since then. Just ask John for the latest programming update next time you get oil change or any other service, he's a great guy!

I'm assuming if You are running an after market tuner then this problem would only be there when You had H2 tuned in factory mode. If this assumption wroung please let Me know. Plus it may not affect 2005 model, would that be correct?
Thanks

TAZ