Transmission Shifting Change / Power Loss after airbag recall

nightkeeper · November 24, 2016

This past August I bought a 2016 GMC Sierra Elevation Edition with 5 miles on it. During the test drive I noticed it had a much stronger feeling transmission with great takeoff compared to my 2009 GMC Sierra WT. I had to be careful not to spin the tires when pulling out (my 2009 felt like it always pulled out in 2nd gear). After 3-4 weeks of driving the Driver Information Center came up with "Service Stabilitrak" and "Service Trailer Brakes". The dealership said that the Anti-lock brake module was bad and they would have to order one. While I was there, they did the airbag recall which was an ECM flash. Immedately I noticed a loss of power when pulling out of the parking space. It felt as if the transmission was in 2nd gear when pulling out. Even if I manually put the transmission in 1st when pulling out, it still doesn't have the power it did before the flash. The dealership said that GM states the airbag recall would not cause any issue with the transmission or power yet the problem existed immediately after the flash. If I push the gas pedal down about half way it sometimes acts like it goes between gears for a couple seconds. Sometimes it gears down and sometimes it goes right back into the gear it was in. I love the look of the truck and the improved ride, but I would have never bought this truck if it ran like this during the test drive. I have less than 3,000 miles on the truck and regret giving GM a 2nd chance. The transmission went out on my 09 GMC at 42,000 miles. It was out of warranty so I had to pay for the GM certified remanufactured transmission that still felt like it took off in 2nd gear. I traded the 09 off for this one when it only had 46,000 miles. The flash was probably the issue with the 1st one... Here I go again...

Has anyone else had this issue? Any resolution without voiding the warranty?

Thomcat · November 24, 2016

Recall airbag didn't do anything noticeable to my '16, rolled out the same way it rolled in. Once the aggressive tire wore in and the tranny smartened up, at over 2K it runs even better than day one.

As a precaution I removed all the flash drives and usb chargers prior to bring it in, figured if they didn't notice and remove them first it could have screwed up the flash.

Dnt · November 24, 2016

Probably not the Airbag reflash that changed the driveability. Most likely it is the bad anti lock brake module. These trucks have tremendous nanny controls and apparently you had one where the nanny was not watching you drive closely enough. That has been fixed by a reflash so you must now accept your fate if you wish to keep your warranty in place....

15 Z71 · November 24, 2016

I had my airbag recall done about 1 month ago and I did not notice any change in power. I do see what you are saying about how good it ran when you bought it. I got mine had 7 miles on it. I came from an 06 Silverado with a 108,000 miles. I think I'm just use to the power difference now. I don't think it lost any.

nightkeeper · November 27, 2016

Thanks for your responses.

If they had changed the part that day, I would have assumed the malfunctioning of the control module was the reason it ran so much better, but all they did (that they said anyway) was read the computer codes and do the airbag recall. If I disable the Traction Control and Stabilitrak, it does run a little better, but nothing like it did right before they did the airbag flash. I sure miss the way it was.

Thanks again

twoheeldrive · November 27, 2016

I had the same problem after the airbag re-program; the transmission got wonky and the truck felt sluggish. I rebooted it (pulled the negative battery cable off for 30minutes) and things went back to normal for me.

gmtech117 · November 27, 2016

I'm sorry, but I have to say this must all be in your guy's heads. That airbag reflash has nothing to do with any performance changes to your transmission.

Donstar · November 27, 2016

If there is a problem with your truck take it back to the dealer for service. I have had the recall completed and didn't notice a difference in how my truck operated. Hopefully I won't notice if the airbag is fixed either! I would write down specific changes you have noticed since the truck was new. I find that the more specific you are, the less likely they are to brush off your concerns. I would be inclined to say you noticed the change around the time of the airbag repair but treat it as more of a coincidence than the cause.

nightkeeper · December 3, 2016

I'm sorry, but I have to say this must all be in your guy's heads. That airbag reflash has nothing to do with any performance changes to your transmission.

They told me that GM said the airbag flash wouldn't effect the transmission shifting, but it was an immediate difference. If it wasn't the flash, they did something else that they won't tell me. The change is definitely not in my head. Before taking the truck in, I had to be careful when pulling out, because it would bark the tire with no effort. When I went to pull out of the parking space after the flash; the amount of gas I had to give it would have lit up the tires and had the traction control light flashing. When I say it changed I mean it was an extreme change. The transmission acts all confused at times and doesn't even want to downshift if I get down on it to pass someone. It's like the truck has multiple personalities: you never know how it's going to run from time to time. I have to make sure there is plenty of room when pulling out into traffic because it may pull out like it's in second gear no matter how much gas I give it. It doesn't even pull out the same from traffic light to traffic light at times on level ground during city driving now. I went from loving my truck to frustration every time I drive it.

I'm hoping the reset will work for mine and will post the results either way. Thank THD

gmtech117 · December 3, 2016

If it's that bad sounds like you should go to your dealer and have the manager or foreman go for a ride with you and see what can be done about it...maybe even go for a ride in another comparable truck..I wouldn't go in saying the "ever since you did my airbag recall " tho, cause there's really no part of that recall that could cause that. Most likely just coincidence. Good luck!

TJay74 · December 3, 2016

The airbag recall does nothing to nor has anything to do with the ECM/TCM at all. The airbag module is its own module and is the only module that is reprogrammed under the recall.

nightkeeper · December 4, 2016

Unhooking the battery for 30 minutes seemed to correct the erratic behavior of the transmission. I drove a little over 100 miles today (city and highway) without experiencing any of the previous issues; the transmission shifted correctly every time.

Thanks again THD

Hope this helps someone else regardless of the cause. Truth is: I have no way to know what the mechanic did while checking my truck other than what they will admit to. All I had was a reference of what they say plus the result that I feel. The fact that 2 out of 8 people on this topic had transmission issues after the airbag recall flash tells me it is possible for others to have the same issue.

FYI: I found with the 2009 GMC truck I owned, while it was under warranty, that if there no indicator saying something's wrong or it's not a complete failure, GM says there is no issue regardless of the details you keep and provide. If the issues on that truck would have been addressed at around 13,000 miles, I most likely wouldn't have needed to buy a transmission at 42,000 miles.

GsBowtie · December 4, 2016

NK,

I feel your pain. I just had my 15 in for service a few weeks back and wanted to take the technician for a ride to show him my multiple concerns with the transmission, but after talking with him about it, he didn't even want to go for a ride with me. He just said "that's normal " and "these transmissions are all over the place, there's nothing we can do to correct it, they are tuned by GM for maximum fuel economy."

While my truck has gotten some better since new. I still get engine lugging vibration in the driveline somewhere, and the occasional clunky downshifting 3-2 .

Of course when I asked why if black bear can correct it, why can't GM there was no response. I have no confidence that I'm going to get good life out of this transmission. I can only hope it lives till i am out of warranty, then i can get the truck tuned.

My trucks shifting behavior did not change at all after the airbag recall, but it did change for the better after the transfer case recall, but eventually relearned it's crapppy shifting characteristics.

I suspect your truck when new somehow didn't have all the torque management these trucks have installed. Your pre airbag flash behavior is an oddity. Your post flash is what many of us experience

.

I bet after the flash your truck went back into learning mode, or the factory trans tune or torque management was somehow activated.

If it's back to what like, that's good and i hope it stays that way for you.

I never know how my truck is going to act. Some days is very good, others, it clunks on every downshift.

It's very very frustrating to have spent all the money on a brand new truck to be told we have to live with it, there's no fix and it's normal. It's NOT normal.

How anyone at GM could have driven these trucks in the development stage and approved them going into production with transmissions like these is beyond me. They should be fired.

One of these days I'm going to take a Saturday and test drive a ram, tundra, titan and ford and compare them to what i have. I bet the GM transmission is the worst of all of them. I hate to consider driving a foreign truck, but that day may eventually come

BlackHawkZ71 · December 4, 2016

I'm sorry, but I have to say this must all be in your guy's heads. That airbag reflash has nothing to do with any performance changes to your transmission.

I agree, I have had the airbag recall done and never had any decrease in performance truck still drives like it did from day one

nightkeeper · December 6, 2016

I drove a coworker to pick up his company vehicle that was being serviced today. He had ridden with me when the transmission was acting up and was impressed with the torque and shifting difference. He even made the comment that maybe he needed to unplug his battery for 30 minutes, because his 2016 Z71 has never ran like that and he bought it new.

Off subject, but a little tip:

If you have your truck put on a lift (oil change, tires, etc.) craw under it and spread the wax back on the frame once you get home (I used my finger). In the event you don't know: GM dips the frames of their trucks in some kind of wax instead of painting them. The issue may not be as bad once the wax has seasoned, but where mine was new the wax pushed out to where bare metal was showing. As you'll see in the picture: after about 3 days, it was already starting to get a little surface rust. The truck was built in July, bought in late August and put on the lift in late September for the ABS Module. Would have had all kinds of rust by spring with all the salt they'll throw on the roads here during winter if the metal would have stayed exposed.