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2007 and newer Chevrolet Tahoe and GMC Yukon



  • Does anyone know where to pick up a switched power source for accessories? With everything communicating on the LAN, I cannot seam to identify a switched circuit that I can power my detector with. Any help would be greatly appreciated. George
  • jmaynardjmaynard Posts: 37
    gcmartin, thanks for your input. From what you state, you have fallen victim to the problem but have not accepted it. The ONLY way Gm will fix this is if enough people complain. I am doing my part. Remember, admitting you have a problem is the first step in getting help!

    Don't accept that because they hand you all this power YOU are responsible for improper engineering and YOU should pay for it. This problem CAN be fixed and GM needs to step up to the plate. Please help by complaining. You have nothing to lose and everything to gain. I promise, they don't kow you well enough to hate you for complaining and the savings that you could recieve would go staight back into your bank account.
  • wlbrown9wlbrown9 Posts: 835
    Isuzu Trooper has what they call 'Grade Logic' that engages the transmission and engine for braking when coasting down down hills. I guess the idea is to keep from building up too much speed downhill. It works pretty well on my '00, even sometimes when I would rather it not downshift and bring the revs up and slow me down :-)
  • gcmartingcmartin Posts: 19
    I have accepted the problem and intend to complain when I go in next time for scheduled maintenance. I hope they will address the issue. Considering that you can program the computers on most cars or even buy performance chips which can increase horsepower, this may be an avenue for aftermarket companies to get into the act. I own a 2004 Subaru STI and I can hook my computer up with a programmer and remap the fuel injection with a download to match the intake and catback. Same holds true for my Kawasaki ZX-12R which has a Powercommander in it.

    It seems that GM could do that when the car was brought in for service. An example would be: Tahoe comes in for service and they download version 2.XX of DOD firmware to the car which addresses issues in V4/V8 mode.

    This seems like a logical step to expect. Maybe GM is not that advanced, but it would seem that they already have the capability and the Vortec DOD is in a continual state of fine-tuning.

    I already called customer service and formally asked about the possibility that a newer firmware could be downloaded at the dealership to address these issues, but I am not sure that it will be heard by the responsible parties.
  • jmaynardjmaynard Posts: 37
    Thanks gcmartin. I believe that they programmed the set that we are currently running using a vehicle with a 4.11 rear axel and even in that situation they took a safe approach to insure that we get the horsepower without a noticable mode switch. As I have stated, it is going to take numerous customer complaints from acorss the country.

    Thanks for raising a red flag where you are. Hopefully others will follow. I will be on the lookout for other 07 owners so that I can spread the 'love' to them.

    You are absolutly right. Someone will come up with an aftermarket chip or program, but if you are like myself, you wouldn't want to invalidate the warranty by installing one. I also leased my ehicle and the lease states no after market parts be installed.

    I agree that they should be able to do it when brougt in for service, the only problem is there is not a newer version available from GM. As far as they are concerned, noone is complaining so there must not be a problem.
  • Just found this site, looking to see if anyone else was getting lousy mileage with their 2007 Yukons. I have a 2007 Yukon XL, with 4500 miles, 3.73 gears (I did not think 3.42 were available) and average about 14mpg. We took it on a 1600 mile trip and only averaged 16mpg. Our best tank, all highway, was 16.5. Our 2002 Yukon XL would average 18 on the same trip. Bummer.

    V4 mode comes on when coasting. Maybe a little when cruising at 60mph.

    The 2007s are a lot nicer than the old ones, I just wish the mileage would be as advertised. It really irks me that we took a step backwards, mileage wise, from our 2002 Yukon XL.

    The dealer service department tells me there are no codes, so there is nothing they can do.

    What number at GM are you calling to complain? I will certainly give them a call.

  • rwernerrwerner Posts: 7
    My LTZ has made two trips from Atlanta to Indy by way of Cincinnati since I bought it in March it has 7k miles on it. On the trips I got as high as 19.5 miles per gallon doing about 5 mph over the speed limit. Also when using it to go to work in Atlanta traffic I can nurse 14 mpg out of it. I don't usually have the DOD up on the display but I'm ok with the mileage. Also I've been a dealer technician for over 40 years most with GM although not now. Over the years doing driveabilty work I learned that alot of the problems we had were software/programing related but found that GM would not update the program in the production year of the vehicle because they would have to recertify with the EPA. Im sure it's the same now. There is no valve action or fuel in the cylinders when in the V4 mode so has to help. At this time I have not seen anything in the aftermarket that will work on 2007 Tahoes as far as reprograming at this time. Let me know if I'm missing something.
  • It's been done and here it is.Nav Override
  • rockman59rockman59 Posts: 250
    At this time I have not seen anything in the aftermarket that will work on 2007 Tahoes as far as reprograming at this time. Let me know if I'm missing something.
    I think the above reference was to reprogramming the engine computer, not the NAV system. But that NAV reprogram kit looks pretty cool.
  • 73shark73shark Posts: 325
    Hope this comes with a flashing strobe light on the roof so everyone can get out of the way!
  • You are missing it completly. This is a hack/bypass for the Nav system NOT the engine computer

    This will allow you to play a video on the front screen as well as programing the Nav while moving.
  • OK...So who's gonna be the guinea pig on this one to see if it works and if so, how easy it was to install??

    I'm interested in this mod but don't want to be the first!!! :D
  • rockman59rockman59 Posts: 250
    To Sovereignmgmt: I thought you were replying to rwerner who was concerned with reprogramming his engine computer to increase his gas mileage. I understand that the hack/bypass for the Nav system is NOT the engine computer. Da!!!! I did go to the Nav sight and watched their little video. Very impressive....and all for $249.95.
  • It works great and it was a snap to install. In fact there is a video link on the install on there page.
  • I'd consider paying that amount if the hack included the ability to use the built in phone system with my current provider and phone. This is one of my biggest beefs with the vehicle, the fact that they didn't put in bluetooth and opted to force you to use Onstar or Verizon.
  • nosbor77nosbor77 Posts: 40
    Check out this article on GM Flex Fuel 1

    Maybe we can get AOL involved to do an article on their AFM fallacy
  • 73shark73shark Posts: 325
    That would make for an interesting article! Another problem with ethanol is that it takes more energy to produce than you get when you use it. :confuse:
  • catahoecatahoe Posts: 15
    Sorry thats just a rumor... Might have been true in the early days but not anymore
  • jay_24jay_24 Posts: 536
    The cost to produce is very much in question. Some say it costs more others say it costs less.
    Biggest issue currently is that most ethanol plants use the kernal of corn to make it. The next generation of ethanol plants will use the stalk, or grass, or other plant materials that are typically waste products today.
  • eliaselias Posts: 1,898
    hi! i really do mean that your vehicle uses zero fuel whatsoever when you are coasting in gear (foot off gas pedal!) - as long as rpm is above some minimum - 1000 or 1500 rpm maybe.
    this is the way fuel-injected vehicles have operated for at least 20 years - i not aware of *any* exceptions and would be awfully surprised if this new Tahoe is an exception.
    it would be counterproductive and wasteful for the ECM to pump any fuel during foot-off-gas/deceleration, as long as RPM is ~1000 or more.
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