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GMC Yukon Reduced Engine Power message



  • gmcustsvcgmcustsvc Posts: 4,057
    Glad that you made it home okay! If we can check into anything for you, please email us at (include your name, contact information, and the last 8 digits of your VIN with a summary of the situation).

    Sarah, GM Customer Service
  • I'm a trial lawyer from California and own a 2007 Denali that had the same engine shutdown problem on a busy street the other day. Paid to replace the batter - 2nd time in 18 months - and the problem reoccurred. Now, I have been asked to replace the throttle body and computer. The mechanic cannot replicate the check engine problem because it is intermittent. It sounds like even the throttle body replacement may not fix the issue.

    After reading most of this thread while waiting in an airport, I am seriously considering filing a class action or at minimum a personal lawsuit. This issue has "defect" written all over it and we have 545 messages addressing this topic alone. That isn't including the multitude of other threads on other sites.

    I'm simply not going to dump $1100 into a "solution" to this problem where it has been proven ineffective. What am I missing here? Why hasn't a recall been issued? Why does the engine simply shut down at 50mph?!
  • I have posted on here before and far as my denali 2005 throttle body was replaced but the truck still has issues i bought this truck used didn't make it to the 90 day warranty been dealing with the problem for about 7 months finally got a lawyer and the dealer is going to make me a offer not sure how much it will be but i need out of this peace of junk.
  • I thought I would let you know that I went through all the same problems. I even told the GM rep that I was talking to that I was ready to get a lawyer and he got really mean with me, and told me if I was going to go that way he couldn't talk to me any more. I only mentioned that because I almost wrecked mine when it quit running in the middle of a turn to get it off the road when it went into reduce power mode. I almost hit another car at the corner because I could not hardly turn it or stop it without the power steering or brakes. If my wife had been driving it I'm sure there would have been damage due to the fact she would not of had the strength to steer it.
    In the end I got my "03 Denali fixed, the dealer had to BUILD a whole new wire harness from the gas pedal to the throttle body. Its a throttle by wire system and they have bad made in Mexico wiring. You can not order this harness from GM they have to build it. A wire should never go bad unless it rubs through the insulation over time and shorts out. And when there is an interruption in the circuit it defaults and goes to limp mode and will only give you 15-20 mph.
    I explained to GM thats like having to change out the wiring every time you have to replace you head light bulb. You should never have to deal with the wiring, unless it physically gets caught on something and breaks, chafes through, or corrosion from moisture i.e. car was in a flood. GM has a real big problem! and to my understanding the new model truck are not covered by warranty on the whole throttle body? If you would like to know more feel free to contact me. I just gave a short and to the point run down on the story.
  • Continuing to have same issue with the reduced engine power light and the vehicle going to 'idle' mode. This is my primary transportation so I try to deal with it. I replaced the fuel filter to no avail. One mechanic suggested the TPS, throttle position sensor. I went to a dealer yesterday to look at new vehicles and told the salesperson about my issue and he said he never heard of it. Really?
    Summary-It seems to go into 'reduced engine power' mode when it sits overnight at 45 degrees or colder. Once it warms up it clears the check engine light and runs. I also have cleaned the air filter(K and N) and sprayed carburetor cleaner throughout the intake. This seems to help somewhat but not solve the problem. Any help would be greatly apprectiated
  • When my '03 Denali first had the problem it was a nice 60 degree day. Like everyone else turn it off for a few min. and it would be fine. I have a mechanic friend whom used to work for a local GM dealer. He told me to go to Auto Zone where they'll do a free scan, and if it's code 220 or something like that it might be a connector at the throttle body. We tried that fix first and for a few weeks it seemed to be ok. Then on a cold night REP happened again. It just kept getting more frequent and worse to where it would quite running, and outside temp. didn't matter. I called GM and they insisted that I get a scam form a dealer, which I told them was pointless. A computer scan will read the say no matter where you go, all they want is your money. My friend told me that GM has a problem with the wires breaking inside the insulation for the throttle body, and since the connector didn't fix it we would have to look at building a whole new wire harness. After many run around with the as always never helpful GM customer service staff, and to what I'm sure they must have trashed talked about me to my dealer. And at which point my dealer was not happy with the way GM handled the situation my dealer did just that. They built me a new wire harness! I did also get a new throttle body. But I am 110% convinced it was the BAD WIRES all the way!!! Knock on wood it's been great ever since!
    I also argued with GM about all the post on this site. Shortly after that I notice GM service agents posting their scripted noncomittal reply to everyone on here, as long as they were using a GM service department. Gm does not care or show interest in those who have brand loyalty. For some reason I bought a new 2011 Avalanche last year. It was a nightmare to get it. I requested it be put on a trailer to get it to me because they had to do a dealer trade. After three weeks of waiting, I ended up going to get it myself and drive it back to my home town 4 hrs. one way. I only wanted it trucked or drive it myself, I didn't want anybody else to drive my knew truck first. Thats how I felt it should be, if it was going to have miles on it I wanted to know how it was driven. After three weeks, getting a one way rental that we paid for and putting $85 of my money into it for gas to get it here. The dealer didn't offer any reimbursement, and GM would only give me a $100 towards maintenance. Then I found out the d--- thing was final assmbled in Mexico. GM is out of touch with the customer, they don't even seem to care when buying new.
    Best of luck I hope this helps?
  • whtlkewhtlke Posts: 1
    2011 Yukon Denali. While driving today I got a "Stabilitrak/Reduced power" message and then no power to speak of. Called dealer and they said its either a cable bundle or the throttle body. They seemed very familiar with the problem. So my $60k car with a whopping 42k miles is at the dealer being repaired to the tune of $600. Realy, issues at 42k miles. After 30 years and 7 GM cars I'm done trying to support these guys.
  • gmcustsvcgmcustsvc Posts: 4,057

    We're sorry to hear that your Yukon has to have some repair work done! If you would like for us to follow up on this with the dealership, we're happy to do so. Please contact us at with more details (including your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation so far).

    Sarah, GM Customer Service
  • Oh wow! I was in the middle of a busy Chicago intersection and I got a traction control/adjust stabilitrak/reducing engine power message and my 2007 Yukon shut down!!!!

    I was terrified! I am going to head to the dealer and I can almost guess they are going to give me an over priced quote with a bunch of dealer jargon that will not fix the problem based on the information I am seeing here. I am scared. Should I drive my car? I do not see why this is not a recall issue. What will it take to get this recalled? Does someone have die because their engine power reduced while driving?

    I will keep updates here on any progress. Hopefully it will help someone with the same issue.
  • died01died01 Posts: 1
    My wife just had this problem today - reduced engine power - had to be towed and her 2011 Denali only has 38k miles. This is really terrible that this type of problem seems to be more than an anomaly based on all the threads on multiple sites yet no notification to owners. We will wait to see what dealer says since car had to be towed to delay 1.5 hrs away from our home.
  • gmcustsvcgmcustsvc Posts: 4,057
    Looking forward to any updates, alsindiana. If you would like any assistance, be sure to contact us at (include your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation so far).

    Sarah, GM Customer Service
  • gmcustsvcgmcustsvc Posts: 4,057
    Looking forward to any news, died01! If you want for us to check into anything, please email us at (include your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).
    Sarah, GM Customer Service
  • My 2007 is having these same problems. It says reduced engine power and only accelerates to 20 mph. Today it completely shut off/ stalled. Dies anyone know the cause and if it's been recalled?
  • gmcustsvcgmcustsvc Posts: 4,057
    If we can check for any open recalls on your vehicle, or help you work through getting this checked out by a dealership, please email us at with more information (include your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).
    Sarah, GM Customer Service
  • rfl2rfl2 Posts: 1
    I have a 2010 Yukon Denali and it just happened to me for the first time this morning. Dealer already fixed it for free under a special warranty code issued by GM for this specific issue. They seemed to know exactly what it is.
  • 2007 Yukon Denali XL 109k. Started doing the same last March. Usually all the dials go crazy, Stablitrak shuts off, check engine light comes on. Sometimes reduced power mode, sometimes not. Usually this occurs in drive thrus, oddly enough, but it's happened on the highway at 70mph a few times, too. I'd say it occurs once a month or so, usually in waves. Neither the GM dealers in Aransas Pass, TX or Boerne, TX could tell me anything about the issue or resolution, and my home dealer in Boerne, which is usually fantastic, just keeps telling me they'll need a few hours minimum just to start diagnosing the possible issue. Frustrating. Happened again two nights ago and Internet searching brought me here.
  • doysterbar1doysterbar1 Posts: 4
    edited February 2013
    I own a 2010 Yukon xl with 42,000 miles and the same thing happened to me on interstate tonight . All the same codes and reduced power as everbody else. I had to drive 40 miles on side of road hoping my children wouldn't be killed. WTF GM, Issue a recall before somebody dies!! Over 550 posts with same issue just on this site, think you have a problem maybe ?
  • gmcustsvcgmcustsvc Posts: 4,057
    We're sorry to hear that you had this experience out on the interstate over the weekend, doysterbar1. Let us know if we can check into this further by sending us an email at with more details (including your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).

    Sarah, GM Customer Service
  • There is special coverage for vehicles under 120,000 miles called "Throttle Position Sensor Replacement" that covered my Incident. I am hopeful this fixes the problem.
  • How'd you find that out? My dealer never mentioned that to me and guess what I just went over that mileage a month ago and had this problem way before 120,000 miles!!!!
    Anyone notice that the burnt out running light might be linked everytime mine burns out I have issues somewhere else.
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