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2010 Chevrolet Equinox Transmission Fix

wallyuwlwallyuwl Posts: 166
edited March 2014 in Chevrolet
I thought the fix to the tranny problems I've described in other threads deserved its own thread.

Today I spent 3.5 hours with the engineer in charge of fuel effeciency for the new Equinox. GM sent him down from Detroit (to Lexington, KY - about a 6 hr. drive) specifically to drive with us. Very nice and very smart. Without typing a novel, I'll tell you what happened.

It turns out to be a tranny programming issue as the dealers thought. The person who actually writes the tranny program for the Nox works under the engineer who came down. Everything I have described in threads on this board as symptoms it did, which was good. The driving characteristics were rather harsh to him compared to other Noxs he has driven, which are many. He was, however, able to explain why every symptom existed except for one (but the solution fixed that, explained below). He did say that although uniformity in parts and software is the goal, small differences happen during the manufacturing process (and GM largely buys parts from suppliers and doesn't make them themselves) that can make one vehicle behave different from another. This might be why some on this board say theirs are very symptomatic, and some say they don't even notice the tranny behavior described.

Without going into specifics, all the symptoms were related to things designed to conserve fuel. Long story short, he put a new tranny program into my vehicle that influences the operation of various transmission and fuel conserving features/components. It actually was just officially approved yesterday, and will begin to be put into new Equinox production vehicles possibly as early as Tuesday (Sept. 22). My vehicle is the first one with this new program that is not a GM corporate vehicle, and only a few of those have it.

The difference is amazing! It drives like a different vehicle. There are still a few small things I'm a little bothered by, I understand why they are the way they are and don't have a problem with them. Although the symptoms we experienced while driving the vehicle were either new to him or more harsh than he's experienced before (i.e.: they didn't specifically make this new program to solve the symptoms I've described), this new program makes a world of difference and solves most all of the problems I've described.

For those thinking about not buying the Nox because of the tranny issues described - don't be hesitant any longer. I no longer discourage people from buying this vehicle because of transmission behavior. If GM is full of people like this guy they will do great so long as people put their biases aside and actually give the vehicles a chance.

For those of you experiencing the tranny symptoms described on this thread and who already purchased one, email me ( and I'll tell you how I understand to get the fix. They may not release it as a full-blown bulletin (there are what I consider good reasons for that based on what this engineer said), so it might not be obvious to your dealer that there is a fix out there, but they should be able to get and do the fix (though I'm not sure on the timeline when the fix will be available to dealers - I would'nt think it would be too long if the new program is going into newly built vehicles possibly this coming week) with a little prodding. The fix is literally a 5 minute thing to actually perform. Also, they may tweak the tranny program a little based on today, but as of now there are no plans to do another tranny program modification on the 2010 vehicle. There are several improvements planned for 2011 model year Noxs, but those can't be loaded on to 2010 vehicles (sort of technical why, he briefly explained that, too).

Also, it is a "learning" transmission, but it keeps "learning" throughout the life of the vehicle. So it isn't just the first 1000 miles or whatever that determine how the transmission behaves for the life of the vehicle. It actually readjusts every 150 shifts or so per gear. This will result in a harsh upshift every now and again (we've had two in two months - one while driving with him today, actually) as a result of a short-shift (he explained this in detail but I don't remember details), so just be aware of it.


  • tidestertidester Posts: 10,059
    email me and I'll tell you how I understand to get the fix.

    Why would you start up a topic only to have people take it off line? Let's keep the discussion here so everyone will benefit.

    tidester, host
    SUVs and Smart Shopper
  • This is great news! I shot you an email on getting the fix.

    Wonder if GM would be able to identify the transmissions affected by this.

    Would you know the programming version number that is to be released. I work for a dealership group and I can have my contacts do some investigating to see when the patch is available to dealerships on SPS.
  • Replied to your email. From the sounds of it all vehicles (at least FWD 4 cyl) should have been affected prior to ones being built with the new calibration (which might be ones starting today). The cals are a little different for 6 cyl and AWD 4 cyl than FWD 4 cyl, though some people said theirs was symptomatic too that do not have a FWD 4 cyl. Not sure how to reconcile the fact some people say they notice no symptoms (even FWD 4 cyl owners) even while looking for them, with the same calibration being put into all vehicles produced prior to today.

    I don't kow the programming version number. I just know it is a new tranny calibration and was approved for distribution/release last Friday.
  • runoxrunox Posts: 156
    That's great ( and impressive) news out of Detroit. Now if GM didn't owe so dang much to the feds, this would be a great stock to pick up. Still is for the long, long run based on what they have on the showroom floor for 2010. Given the economic outlook through '014, it could take some time to bolt upward.

    Since there aren't that many '10's out on the road right now, it would make sense to publish this as a SB and reprogram them as they are brought in for a service review.
  • vrmvrm Posts: 308
    Thanks for the detailed post. Its good to know that the new GM is proactive.

    I was sitting on the fence - I wanted to buy the 4cylinder engine but was afraid of all the transmission complaints.

    I will visit my local GM dealer next week to test drive the 2010 Equinox.
  • what if the mpg is now 17/27 instead of 22/32?
  • wallyuwlwallyuwl Posts: 166
    Haven't noticed any difference in fuel economy after the new cal. Still goes into the fuel cut off mode, the main differences are with the new lack of downshift when accelerating slowly while at high speeds and with the torque converter operation at lower speeds. Again, with the new cal things don't feel "normal" like we are used to with most automatic vehicles because of the fuel cut-off stuff, but the "bad feelings" are much improved with the new cal. I still hope they come out with another one in a couple months that improves things even more while maintaining most of the fuel-saving things - from talking with the engineer it seems like a few things can still be tweaked. Don't know if they'll do it or not.
  • What do you mean "with the new cal things don't feel "normal" like we are used to with most automatic vehicles because of the fuel cut-off stuff"?

    I'm very interested in this because my dealer called to let me know about a transmission callibration update. Calibration bulletin #09271 issued on 10/8/2009.

    This update is supposedly to improve transmission shift characteristics for downshift hesitation, delayed shifting, and shifting at the wrong time.

    The way it was described to me was that they would take the info from my Nox's computer and upload it to GM's computer to get the correct update.

    I guess I'll give it a shot. According to my dealer, "it's not for better gas mileage", which I could use, "but if it's shifting wrong, it's probably using more gas than it should "

    I'm experiencing some, but not all, shift characteristics described in the bulletin, so I suppose I should try it.

    Has anyone else had this update performed?

  • wallyuwlwallyuwl Posts: 166
    Thanks for the info. Any way you could find out the actual calibration version number and not just the bulletin number?

    I'd bet that is the same cal as the one I received from the engineer who came down from Detroit about 3-4 weeks ago (as of this coming Sat. - don't remember if it was Sept. 19 or 26th he came down).

    The one I got installed was only officially approved the day before he came down and probably took until now to get to the dealers. However, I do not know the exact calibration number he put in my vehicle. It is far better than the original cal., however, though still not ideal. He did say that they did not plan on doing any additional new cals for the 2010s, but after getting lots of data from my vehicle they may do yet another cal he said. So since it took several weeks I do sort of wonder if they did this and this new one you mention is because of that, or if it is the one I got.

    I am going in to get the rear bumper adjusted (wasn't put on quite right) early next week and will see if they will check my calibration number.

    In either case (if the cal is the one I have or an even more updated one) I'd get it. The driving experirence will be much improved in either case.
  • I just got mine flashed as well. The process is very straightforward, I kinnda hovered over as they did it. The tech hooked the MDI to the Nox and in Global Connect went to SPS, then selected the correct vehicle. Then they are presented a list of all the modules you can program (long list about 20-30 items). They first looked at the TCM (Transmission Control Module) and within it there are 3-4 different parts that can be upgraded. Sorry I did not get the exact version numbers, but all the version were shown as a tree and the one at the bottom is the latest. Mine was just one up from the bottom, so it did need the flash. But then there is an information message that says the TCM and ECM (Engine Control Module) must both be programmed. Then going back main modules list there is a SEQ module that flashes the TCM and ECM together. They did the update, it took all of 3 minutes for the TCM and maybe 5-6 for the ECM.

    I’m impressed with the driving dynamics of the new flash. I no longer experience high drag when decelerating around 30 to 20MPH. I think the third gear TC lockup is no longer shuddering. Also I think the idle performance was tweaked, it’s a very smooth with ECO off, and smoother with ECO on (you can still feel just a slight shudder). I also think it cleared the learning memory, as it wanted to hold gears a little longer, rev a little higher than I was used to. I baby it and drive to get the best fuel economy, so it will take a little time for it calm down (Ha!). After only 50 miles I already see it adapting to my style.
  • Sounds good, I'll be getting mine tomorrow and will try to get a version number.

    They told me it would take about five minutes, but sometimes they've had to wait an hour to get GM's computer online.
    I'll be glad to lose the drag when decelerating around 30 to 20MPH most of all, but it sounds like GM is really trying to tweak the performance.
    Looking forward to my second first drive ;-)
  • Hi guys -- I assume these new calibrations are covered under warranty, yes? (And therefore don't cost you anything to have the dealers update the system?) I got my new Equinox on Sept. 26 (build date was about 2 weeks earlier) so I'm guessing I don't have the most recent calibration. I haven't noticed any particular shifting issues, but it seems to me that if GM thinks these new calibrations are better, then it's probably best to upgrade. I also have a little squeak that seems to be coming from my driver's side rear passenger door (or perhaps wheel well) when I go over bumps so maybe I can have them try to get rid of that at the same time. It's a pretty minor squeak but is starting to annoy me. Anyone else had to deal with any rattles or squeaks? Overall, I love the vehicle so far though.
  • Yes the flash was covered under warranty. There is a bulletin about the transmission calibration posted earlier, any dealer should be able to locate it. That bulletin plus a customer complaint should be all that is needed for it to be covered.

    My Nox only has two rattles that I need to get looked at. One is in the inside rear hatch door, sounds like a screw or clip that is loose inside the door panel. The other sounds like it is coming from under the passenger seat. I only hear it when going over bumps, so it’s kindda hard to narrow down what it is.
  • I had the the service update performed today for service bulletin #09271A and not only is the Nox shifting smoother, but according to the computer, I'm getting much - MUCH better gas mileage. I was getting much worse mileage than what others have reported before today, so ymmv. I haven't tried Eco Mode yet, but the smoothness in Auto Mode is really night and day from the bumps I had between gears before. Both upshifting and downshifting. Pretty close to "like butter"! Highly recommended!

    Like snawdjj, I see it reving a bit higher and I see on my service records, "Clearing DTC's will erase stored history data from all controllers and will reset the PCM I/M flags." That's exactly what it feels like. So it's like starting over - cool with me ;-) Dealer even washed it for me...nice.

    Out of the 6 ID's for the ECM Controller, I had flashes performed for ID #2 and #6.

    #2 went from number 12635385 to number 12637998 - New calibration with improvements to AC Compressor Anti-Slugging.

    #6 went from number 12636340 to number 12637996 - Modified shift pattern for improved driveability. - Must also reprogram TCM with latest calibrations.

    Out of the 4 ID's for the TCM Controller, I had flashes performed for #2 and #3

    #2 went from number 24255400 to number 24256213 - TCC Coast Mode and On Mode improvements, Shift Quality Improvements.

    #3 went from number 24255170 to number 24256215 - TCC Coast Mode and On Mode improvements, Shift Quality Improvements.

    All for now, but keep the experiences coming so we all can compare notes.
  • Anybody know where I can get a copy of the service bulletin (#09271A) for the new calibration? I did a quick online search and didn't come up with anything. I always like to be able to bring in a copy of the bulletin when I go to the dealer so there is no misunderstanding.
  • I'm wanting the bulletin also, I would feel better having it with me when I go to the dealer. I can't find it either.
  • I forgot to mention, my idling rpm is about 300-400 rpm lower now. Slightly lower in gear than in neutral.

    I've been in Eco mode since the last post and I've been really standing on the gas to max out rpm's and it's shifting really smooth. If I'm going real slow, like over multiple speed bumps, I still get a little lag between 1st and 2nd, but it's absent during all other driving conditions.

    Me likey :)
  • wallyuwlwallyuwl Posts: 166
    Ok, so I went to the dealer yesterday for a bumper issue, and also got some cals redone. Here are all the latest cals for each of the 8 modules of the ECM (note: this is for FWD 4 cyl, other versions may differ):

    1. 12636334 - main operating system, replaces 12635812
    2. 12637998 - new calibration with improvements to AC Compressor Anti-Slugging
    3. 12635381 - incremental release RPR2.
    4. 12635389 - same as above.
    5. 12636342 - new calibration with diagnostic enhancements for DTC P219A
    6. 12637996 - modified shift pattern for improved driveability. Must also reprogram TCM with latest calibrations.
    7. 12633518 - New software.
    8. 12634344 - new calibration for start of production.

    Some notes - the #6 new cal is the same one I got from the engineer about a month back that I've talked about on here. It is the final tranny cal they plan for the 2010 Nox. It still "jack rabbits" or "lunges" a little downshifting from 5-4 and 4-3 in non-ECO mode. In ECO mode, however, things are pretty clean. All upshifts are fine IMO. I'd suggest driving in ECO mode in-town, and on the hwy for passing or if you are in heavy traffic then use regular mode since you won't be getting to a slow enough speed where these "lunges" will be felt anyway. For hwy cruising I'd use ECO mode for the lower RPM and better mileage.

    I don't know which cal fixed this problem, but the new catalytic converter cal I mentioned previously is in this new set of cals. I no longer get the jitteriness when first driving when the vehicle is cold.

    Things are pretty good now that they fixed these things. Hope this cal. info. helps some others. They still may release other new cals periodically, but they won't be for the tranny (as is my understanding).
  • The ECM ID's 1, 3, 4, & 5 are what came from the factory as of August 2009. I'm not experiencing the "lunges" you describe here and I'm finding Eco mode much better than before, even when passing uphill on the freeway, which is surprising to me.

    You did get the TCM Controller Cals that go along with ECM #6, right?

    I listed the TCM Cals (2&3) that are necessary in my last post, but the other two that are still at the factory specs as of August are:

    TCM ID #1 - 24252872 - Operating System

    TCM ID #4 - 24255172 - New Cals for RPR2 - Modified adapt properties to improve green drivability.

    Now there's a complete list of controller ID's, online, for the 2010 Nox.

    Thanks to my dealer for letting me know and to wallyuwl for putting up all the ECM's. It didn't dawn on me that all the production months may not have all the same Cals.
  • wallyuwlwallyuwl Posts: 166
    The paperwork I got only listed the ECM cals, not the TCM ones. I think they just gave me what I asked for, not thinking to ask about the TCM (doesn't seem like they give any of this info. unless you ask for it). I'd guess they also did those because it was recommended for the ECMS and I doubt things would work if it wasn't done. I don't know this for certain, though. There were also two print outs that contained different version numbers of updates (sort of hard to explain), but otherwise didn't say anything else. Had a picture of a car and hand held computer on it. But I threw those out because I didn't think they had any important info., but it is possible one was for the ECM and one was for the TCM.

    When I need an oil change (maybe not until over X-mas while in WI for the holidays) I'll also have them look for any new ECM or TCM updates. They are more competent up there, anyway.

    It does seem they are updating cals like crazy on this vehicle. I know it is new, but geeze! Maybe I'm wrong, but it seems like there are major revisions being done on this thing to the cals, even for a new model.
  • wallyuwl,

    It sounds almost like the print out that I got, but with a printing problem. Like maybe the printer wasn't formatted for the size of the document or something. As a matter of fact, if your papers were printed vertically, I would guess that's what happened. My Controller page was printed horizontally with the word "Summary and my VIN at the top.
    The page with the picture of the car and computer was the last page that stated "programming complete" and gave the warranty claim code number S1AB5. It also contained that line I wrote about Clearing DTC's will erase all stored history.
    I think the 2 TCM Cals are, one for up shifting and one for down, but I'm guessing.

    While I was driving up the fairly steep freeway to my moms today, I noticed that, while in cruise control @75mph in ECO mode, it wasn't downshifting like it used to do before the calibration. Very low revs in 6th and when I took it out of cruise control and slammed the gas, it downshifted and revved to almost 5k before shifting to 6th. It was a nice smooth burst of speed. It was at this time that I thought that this isn't some $60,000 Benz ML350, this is a $23, something Chevy and for what it is, it is really remarkable.

    I don't look at these cals as major revisions, just tweaks that probably most people won't even need.

    It's not a perfect vehicle in every way and may have had a few bugs at the starting gate, but it is a very well balanced piece of machinery that I have no remorse over purchasing.
    And I'm the king of taking things back and complaining, so if you knew me that would mean something ;-)

    Hopefully 10-20K miles down the road, I'll feel the same way :shades:

    Btw, I see that you were the guy that probably got the engineers attention about this, so bravo to you :)
  • wallyuwlwallyuwl Posts: 166
    Our papers with the pictures are the same, then (different warranty claim nos). Wish I hadn't thrown those out. So you're saying those are for the TCM? The ECM print out with the controller IDs also printed landscape, but just had the ECM stuff on it.

    With the 5th and 6th gear thing, that is new with this new tranny cal. They made it less likely to downshift when accelerating (or pushing on the gas going up a hill even w/o acceleration), but the RPMs do increase while still in 6th for more power.

    I am also pretty happy. I think the tranny cal could still be tweaked some with the downshifts from 5-4 and 4-3 (wish they'd just keep it in high gear and go down to 1 at a stop like trannys used to instead of downshifting on the way down), but overall I'm content with how it drives. And the rest of the vehicle is superb, especially for a mid-$20k price point.
  • All my ECM and TCM info was printed on one page. Five columns.
    Controller - ID - Current# - Selected# - Description

    ECM -1
    - 2


    If I have a way to send you the info, I'll scan the sheet for you.
  • When did you purchase your Equinox?

    I received mine in late August and when I took my Equinox for an oil change today (it had around 2,500 miles on it) the service guy told me that there were no new calibration version numbers for my equinox. I even printed these pages out and gave it to him too.

    Do you think I was given the run around and they did not want to take their time and install the calibrations?
  • wallyuwlwallyuwl Posts: 166
    If you have a FWD 4 cyl and you are in the USA, it is possible they were being dishonest with you. I don't know how things are in Canada or with other versions of the Nox. All Chevy dealerships should have the same systems available to them to access updates such as this from GM, unless it is not an up to date dealership in terms of their equipment.

    On another note - why are you getting an oil change at 2500 miles? :surprise:
  • wallyuwlwallyuwl Posts: 166
    No need to scan. Mine was like that only it just had the ECM updates. I'll see what I can do about verifying I have the newest TCM versions (could you post those? Maybe you have and I missed it.). I don't even know if the new ECM ones work without the new TCM (thus leaving the vehicle undriveable) since it says specifically to update the TCM with some of hte ECM. Anyone else have an idea?
  • I guess I'm old school and like to have the first oil change at under 3000 miles if it is a new car. Also, the lower weatherstripping (on the body) on the drivers door was coming loose so I had them fix this too.

    Mine is a FWD 4cyl and I live in the state of Maryland, USA. This is a large Chevy dealership in Gaithersburg, MD (Criswell Chevrolet) and I think they are being dishonest with me.

    Do you have any suggestions on how can I find a dealership that will update the calibrations for me?

    Thanks in advance.
  • wallyuwlwallyuwl Posts: 166
    Just find another dealer and tell them you want your vehicle checked for the latest cals. Print off the list of cals from the forum, but don't show them to the dealer. But, tell them that if you have the latest cals to print off a list of the cals on your vehicle from their computer. Then if that list doesn't match up with your list, ask them about it. Although sometimes dealers will treat you better or worse depending on whether or not you bought the vehicle from them, they still get paid for warranty work the same from GM, so really you could just try the next closest one.
  • I'm with wally, (just call me beaver ;-), I think any Nox on the lots or delivered in August would have some upgrade numbers for them. Your service guy is mistaken; I'd bet.
    Here's the summary from my flash. The marks on it are from the mechanic.
    Have a mechanic hook your Nox up to the GM computer and have a look for yourself.
  • Thanks for all of your help (rocketent, wallyuwl) I did not purchase my Equinox from this dealership (because they could not get one for me to take advantage of C4C). The dealership I bought it from is over 70 miles away and not convenient for service. I will try another dealership and will keep you update.

    Thanks again!
This discussion has been closed.