Owner's manual does not tell you to check the fluid, the 8l90 has no dipstick. Take to dealer if visible fluid is leaking. Available to the public if you wish to check it your self, the procedure from gm list the steps and temp to properly check the trans fluid. And in the list states to test drive till temp is reached , but also states that in the service bay it my be nessary to brake stalling the trans for 10 seconds at a time to reach the proper temp. However I am totally against that as you can do severe damage. The service fast learn and individual clutch learning procedures are specific to each 8l90 platform. It may over time learn where it needs to be but I'm not 100 sure as I'm not a certified gm tech. I posted this here in this section " Ask a gm technician" with thoughts of getting a answer from a GM technician. I did talk the service manager again, and he said he missed it on the bultion. After reading it I understood how he missed it.
The 8l90 is a little more complicated then just disconnecting the battery to reset parameters. The service fast learn can only be done through the GDS2 and tis web as I understand it. As far as brake stalling the trans to bring it up to temp, gm actually list that a step in checking the trans fluid in the 8l90. I know it's ridiculous, Gus's they want to cut down on time. I don't want them doing that tie mine which is why I wanted to bring it in and have them do it then.
I just got my 2018 Silverado LTZ 6.2 with the 8l90 8spd back from the dealer where I had a TCM calibration update done, it was for improved shifting. They called and told me it was ready for pickup. I read over the work order and noticed that there was nothing listed that said performed service fast learn after installing update. So I asked the service manager and he said he would ask the tech if he did it or not. Service manager said it was not done. They said I can bring it back in to have it done if I wanted no problem. I have read over many service bultions pertaining to the transmissions, and they all state that when a TCM calibration update is done that the service fast learn is to be done as well to reset the parameters and shift adaptation. I've been driving it around for a few days and it feels as though the truck shifts better the more I drive it. When I first drove it home it felt like the tq converter was locked all the time and it didn't want to down shift till the peddle was wide open. The motor would kinda bog for awhile or stay in a higher gear longer before it would shift. My question is should I still go back and have the service fast learn procedure done. My truck only had 1, 800 miles. If I keep driving it without having the fast learn done, will it eventually learn it's self where it needs to be or should I just take it in and let them do it. Also what exactly is the service fast learn actually doing. If I take it back I wanted to take it in and wait on it so it doesn't sit over night and cool down, as I believe the service fast learn is done in the service stall and has to be at a certain trans temp . I didn't want them brake stalling the trans to get it up to the required temp. The service fast learn is different from the individual clutch learning process. Thanks in advance.
Crobinson16 replied to NIXONRIDE's topic in 2014 / 2015 / 2016 / 2017 / 2018 Silverado & Sierra Accessories & ModificationsI've been trying to find a cluster for my 2018 LTZ Silverado. You have some numbers posted of what may work based by year. Any possibility of any new numbers available to use for the 2018s. If so could you post them, thanks.
I just thought of something and perhaps Justin will chime in, think about this, is the fast learn something that needs done? When someone tunes there truck through any of the tunners. We don't do a service fast learn from the dealer. I know the don't tune the 17+ 8sps but some of them have tuned the 14-16 8spds and I don't think they tell you to take it back to the dealer for a service fast learn. Just something I thought about.
Actually I just read one of the bulletins, and it does say that if a TCM is reprogrammed, a service fast learn is required. So I'm going to call them tomorrow and see what they say.
I just had my 18 6.2 at the dealership for a TCM program update it was for improved shifting, they did not do a " fast learn " on the trans. I don't know if they are supposed to that after a reprogram or not. I'd like to find something that says they should. A fast learn only corrects clutch fill times I don't believe it has anything to do with shift points or tq converter lock up.
Crobinson16 replied to brendan4862's topic in 2014 / 2015 / 2016 / 2017 / 2018 Silverado & Sierra Issues, Troubleshooting, & Recalls/Service BulletinsYea I've been looking for a 2018 cluster for my LTZ 6.2 max tow as well. There are only a few numbers out for the 18s there is a list somewhere, not sure if it's been updated to include anymore numbers for the 18s or not
Crobinson16 replied to langston1726's topic in 2014 / 2015 / 2016 / 2017 / 2018 Chevrolet Silverado & GMC Sierra 1500I like the graphics you have on the lower door, would you mind sharing where you got them. I sent you a pm as well. Nice truck by the way
Crobinson16 replied to spenpet's topic in 2014 / 2015 / 2016 / 2017 / 2018 Chevrolet Silverado & GMC Sierra 1500I haven't seen that one, although if you go to the TIS WEB site that was provided you can type in your vin number and what module or controller you want to check and see what may be available. I did this for my 2018 6.2 8spd and found that there is an update available for the TCM titled "transmission update to improve shifting" . I posted a picture in my previous posts.
Crobinson16 replied to spenpet's topic in 2014 / 2015 / 2016 / 2017 / 2018 Chevrolet Silverado & GMC Sierra 1500Just thought I would give an update, finally got to take truck to the dealer, they hooked it up and the update was available, as listed in the tis web. I asked them before I took it in and they said the same thing as you did, that wouldn't know if it was already installed or if it could be installed until they hooked it up. Drove it home and it's different different, don't know how it will truly be till I get some more miles on it and it adjust. I did notice it holds gears longer in all driving conditions. Not as much shifting between gears or possibly seems the tq converter stays locked longer but that could change after a couple miles. Good or bad I dont know yet. Also the the constant up shifting in traffic and low speeds has seemd to not be prevalent.
Crobinson16 replied to Crobinson16's topic in 2014 / 2015 / 2016 / 2017 / 2018 Silverado & Sierra Accessories & ModificationsThey use 3m adhesion tape, I did put them on the truck with tape just to see what they would look like I have pictures posted in the previous page
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