GM AFM Design Flaw Woes (Stabilitrak, Traction Control Service Lights)

Discussion in 'Chevy Tahoe Forum (GMC Yukon, Cadillac Escalade)' started by msw007, Mar 13, 2013.

  1. msw007

    msw007 New Member


    So I would like to discuss our recent troubles with our 2007 Chevy Tahoe LT 5.3L. We were finally able to purchase our first new car, 2007 Chevy Tahoe LT, ever in October 2006 from our local dealership. We decided on the Chevy Tahoe because we have had a used Chevy Suburban and Used Chevy Tahoe prior and have had excellent experience with both of them. It was truly a wonderful experience until now.

    Flash forward to October 2012. While traveling several warning lights came on “Service Traction Control, Stablitrak, and Service engine”. We brought it to the dealership a few times to scan for a code and they couldn’t come up with anything. So now we had to wait until it was actually happening and rush it over to the dealership so they can scan for the code while it was happening. Finally it was happening enough that we were able to get it to the dealer for the scan. The scan revealed that spark plug #1 was fouled and would cause a chain reaction on all the computers to go haywire. So they did a little research and they found a GM TSB (technical service bulletin) that said replace the valve cover gasket, replace all the plugs and wires. Keep in mind these are 100K mile platinum plugs/wires and we currently have around 79000 miles on the vehicle (GM recommends replacing these items at 100K miles). So we did what we were told and $700 later we were on our merry way.

    Jump forward to January 2013. Now we start hearing a clunking sound on acceleration. We bring it back to the dealer and they can’t seem to find anything (of course not????). Now February the sound is more apparent and all the warning lights have come back. I decided to take the car to a friend of mine who has a local shop and specializes in foreign autos. I knew he would take the time and do the research to finally tell us what the dealer couldn’t. After having the car for a week the verdict was in. GM has this fuel management system introduced on this particular 5.3L motor in 2007. It’s supposed to be able to switch from 8 to 4 cylinders and back to help save on fuel (Active Fuel Management or AFM). To confirm the problem he would have to tear down the engine and check the intake valve on cylinder #1. This is when I said “I’m taking it back to the dealer”.

    Now the dealership has the car and I didn’t mention that I already had it looked at. I wanted to see if they would come up with the same diagnosis. Well after a week they did. I can’t believe it since the initial $700 fix 3000 miles ago in November 2012 I now have to replace the engine, WTF! Needless to say I was not a happy camper. Now the car has been out of warranty for a little over a year (which has been pointed out to me over and over again) but that’s not the point. The point is we bought a brand new car so we wouldn’t have any problems usually associated with used cars. A car that has less than 100K miles on it. A car that has been religiously serviced by our local Chevy Dealership. And now I’m being told I have to replace the motor!

    The dealership called GM. GM was quick to say they would replace the motor and cover 50% of the costs? Well whoop de doo. Why were they so quick to offer that deal? Of course they are replacing it with a genuine GM remanufactured motor with a 3 year/ 50K warranty and that’s all they are willing to do. I don’t expect the dealership to cover all the costs and it would be nice if I wasn’t out of pocket any. Yes I know the car it out of warranty but I expect GM to back up their product. Did I mention I have purchased over $100K in new Chevy vehicles over the last several years.

    So the car is no good to us. Can’t drive it, sell it or trade it in. I basically have to take the deal. My estimated out of pocket will be $3K plus tax.

    So I decided to call GM directly and talk to them in a kind Christian sort of way (as only I can do). I figured if they heard from the customer directly that they would be willing to at least come down a little. I know the car isn’t under warranty. The results were not what I was looking for. After they gathered all the information from the dealership and me as well they will only cover 50% of the cost. I explained to them that I’ve been a loyal customer, this car had less than 100K miles on it, I’ve spent over $100K in Chevy cars over the last several years. Nope all they would do is 50%. I asked would they would at least reimburse me for the $700 that I already spent that was totally unnecessary? Nope only 50%. Well let’s just say things went pretty much south from there.

    So here is where we stand. The dealership is putting in the new motor. They are working with me to get the price down under $3K. I don’t begrudge the dealership I think they did what they could do (as personally later found out with GM). I don’t begrudge the lady at GM I’m sure she has set parameters she has to follow and she’s just a drone in the corporation. However I do begrudge GM for not standing by their product. Do the research it’s all over the internet. GM has a problem with this motor and it’s “Active Fuel Management” they know it and they will continue to have problems. Unfortunately if you do have this particular motor there’s no way to check if you will have this problem or not. I will never buy a GM product again. They have lost a loyal customer over $700.

    I find it pretty amazing when they want billions of our tax dollars to bail them out and I'm looking for $700 just does not compute with me.

    Feel free to share this and let's set GM straight that they should stand behind their product!!!!
  2. Pikey

    Pikey Moderator Staff Member 5+ Years ROTM Winner 5000 Posts

    I am sorry to hear that you had such an issue. I was in the same boat with my wife's torrent. It was under warranty and they wanted me to pay to fix it. We sold it before things got worse. They did offer me an extended "component coverage letter" that would have covered everything for another year after I paid to find the original issue. I am surprised that they suggested a new engine before they did the piston and ring swap that they are doing to a few guys trucks on here. But, their trucks are still under warranty.
    Here is a thread with other members that have had the same issue:
    I would send a PM to Evan @GM Customer Service
    . Send him your vin, address, mileage, dealer and a quick rundown of the issue. You may get the same old line you have been getting, but who knows maybe he can help you out.
    Last edited: Mar 13, 2013
  3. stchman

    stchman Active Member 2 Years 1000 Posts

    I sympathize with the OP. I am on my 2nd 5.3L engine (first one in my 2008) and no problems so far.

    I am going to say that GM has sold millions of 5.3L AFM engines since 2007, and only a handful have exhibited the problem the OP has talked about.
  4. msw007

    msw007 New Member

    I spoke with GM directly and they would only offer 50%. All I wanted was the $700 that I already spent to be taken into consideration. This will continue to blow up in their face. I'm thinking class action lawsuit. Thee are enough people out there that have this problem and with those model years getting up in mileage this will become more apparent.
  5. GM Customer Service

    GM Customer Service Epic Member 5+ Years 500 Posts


    I'm sorry you are frustrated. Could you private message me your case number so I can look into your situation?

    Evan, GM Customer Service
  6. Enkeiavalanche

    Enkeiavalanche Loving the Outdoors Staff Member 5+ Years ROTM Winner 5000 Posts

    GM Wake UP!!! More and more people are having these problems and we don't want BandAids on our $40K + Trucks...
    Last edited: Mar 13, 2013
  7. BillD64

    BillD64 Rockstar

    OP. I suggest you gather copies of all of the bills and and write a letter to the President of GM (Mark Reuss ). Don't go into the long story here you posted here. Just mention the engine failure and that you think with less than 100K miles on the engine you would like GM to cover the complete cost of the repair and then tell him how much money you want (this is key when writing letters to any business as they need to know exactly what will make you happy). Provide copies of all bills to replace the engine. One of the reasons I am a loyal GM Customer is because I have received positive responses from them on several occasions and they have given me all that I have asked for. At the time my car was over two years out of warranty. The President of GM will not actually see the letter since they have people assigned to handle such things and then report back what they did.

    Now the reason why you don't want to discuss the issue of the previous repair and any of the Service Messages. First, the previous repair may have fixed an issue that existed then and was separate from the one you have now. Nobody knows so don't make an issue of something that you can't prove.

    Neither problem was resulted in a chain reaction that caused the other computer systems to go crazy. Traction Control and Stability Control are functions of the ABS and depend on the ECM being able to reduce torque when the EBCM requests a torque reduction. Both failures affected the ability of the ECM to properly control engine torque. When that happens the ECM sends a message to the EBCM that it can't do its part of the traction control and stability control functions. The EBCM then sets a diagnostic code that says the ECM has a problem and that causes the Service Messages to be displayed. So what you were seeing is a planned reaction to an engine problem that affects torque control. A driver may not realize that a check engine light or service engine soon message might disable traction or stability control and get into trouble if they were expecting those functions to work properly. That is why those messages are displayed. Since that part of the vehicle's system is working properly you don't want to get into a discussion of GM's failures when they know it isn't a failure. You want their focus on the actual problem not non issues.

    If a mechanic told you there was a chain reaction causing the other computer systems to go crazy I would suggest you avoid that mechanic from now on since he/she doesn't understand what is going on. If it was your interpretation of what you were told you aren't the only one. I see these comments from all sorts of people who have some sort of an engine issue and get all bent out of shape over the service tc and stability messages.

  8. msw007

    msw007 New Member

    Do you have an address where to send such a letter?

    The previous repair was based on a TSB by GM. GM also has more TSB in regards to this problem. In fact the dealership was told by GM engineering to scope out the cylinder in question. They knew exactly what to look for. When it was confirmed GM's response was to replace the engine not rebuild? I find this all very interesting.

    In essence the original TSB was to hopefully (in GM words) to remedy the problem. The fix lasted less than 3000 miles.

    I really believe GM know they have a problem. I also believe that GM is betting on the come that these problems will start to happen after the magical 100K miles (normal mileage puts that out almost 7 years). This way GM can play the age of the car, mileage, and anything else they can think of.

    I'm a business owner in a small town and to throw out all the business I have given them over the last 10 years is just plain stupid (over $100K). In reality all I was looking for was the $700 reimbursement for repairs that were not needed to bring the bill down to around $2K. If GM was to pay for the whole thing then I would have no problem with that either. If I had a customer that spent that much money with me over the years then I would do whatever I could to make them happy. Even if it cost me some money short term I would know long term I would have a happy customer and make my money back. Apparently GM has a short term, reactive mentality not a long term proactive thinking process.

    After speaking with the owner of the dealership where I purchased and had the car serviced from, he told me that most of these car companies are starting to standardize the way they handle claims. They don't want to open themselves up to any law suits that claim discrimination in any one case. Meaning if they were to replace one person engine over another then why? I can understand that as business owner that you would want to treat everyone the same.

    My gripe with GM is that there is an obvious design flaw and this will continue to be a problem. From my understanding they made some modifications to this motor in late 2009 early 2010 so was it to make it better or fix a problem?

    We can discuss the mechanical details on why this happened or not. The bottom line is in this day and age you shouldn't have to replace an engine with less than 100K miles on it. I can understand belts, hoses, valve cover gaskets, batteries etc. but an engine. Plus the poor dealerships have to deal with this and they are not getting any support from the mothership.

    I'm sure there are enough disgruntled GM owners that we could have a class action lawsuit against GM. It may take awhile put public opinion seems to be on the side of the consumer and not GM.

  9. BillD64

    BillD64 Rockstar

    I just did a search on the internet and found the address. Pretty easy to find. Corporations are not giving up their ability to be magnanimous. They have been following the so called Standard Process you used for decades. The President of a Corporation can decide to award compensation based on a letter sent to them. One thing they all want to do is to settle an issue with a Customer in the best way possible. It helps considerably if they know what will make the Customer happy. To this point you have been dealing with Customer Service flunkies. With a letter you are basically asking for a higher level review of your situation. I remember the dealer I purchased my GM vehicle from calling me and saying my letter (I hadn't copied them) was a fruitless effort. Two days later I received a check for several hundred dollars from the dealership. A day later I got a call from a manager in GM asking if I had received anything from the dealer and then he told me I would receive another check from GM for the remainder of what I asked for. He also gave me a phone number to call if I had any other issues and a chit for a $2000 discount good for a year on the purchase of a new GM vehicle. The chit could be used with any other offers. Two years later I called and asked if they could renew the chit which they did and I purchased a new car at a substantial savings.

    None of us know whether or not GM has a problem with the engine comments like that are pure speculation. As a business man how would you like people ruining your Customer relations by making unsubstantiated claims about issues with your products or services. You personally know of only one engine out of several hundred thousand. Remember it is very hard for anybody to be magnanimous towards you if you piss them off by making wild claims, etc.
  10. msw007

    msw007 New Member

    I found an address on the internet.
    After I get the final bill I'll try it your way. I will send a letter and explain how I don't think I should be replacing an engine on a car with less than 100k miles.

    As a business owner it's my business to make sure that we as a whole company treat all of our customers with respect and honesty. I also make sure my company gives anyone reason to make false claims. This is how my family company has been able to survive for four generations. This is how we have been able to survive. This is something that GM seems to have forgot. One of the many reasons why they went under.

    I have never made a wild claim. The facts are simple the particular AFM on the 5.3L does not work. The result a new motor in our Tahoe. There was also design change in 2009-2010 to this particular motor. There are plenty of people out on the internet on various forums that have had the same problem which resulted in either a new engine or a complete rebuild. It has been well documented and GM's own TSB's have made references to a problem. This is a fact from the actual GM dealership. So is this an unsubstantiated claim? I think not.

    I thank you for input and I have been a little hot under the collar for a couple weeks now. I'm sure calmer heads will prevail. I am encouraged and have seen others do what you have suggested and they have also been successful. We'll see.


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