Last post on Mar 05, 2009 at 3:20 PM
You are in the Pontiac Montana
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Pontiac Montana, Pontiac Montana SV6, Van
#1 of 5 2000 Montana cuts out
Mar 05, 2009 (8:32 am)
I just had my tranny rebuild and it was still showing codes to replace computer which the mechanic did and reprogrammed. I had the van back for 2 days and while driving it cut out 4 times as well as shifting hard again. Any idea what it could be?
#2 of 5 Re: 2000 Montana cuts out [cbish]
Mar 05, 2009 (9:02 am)
Curious what he did... did he replace trany with rebuilt or did he replace only complents in it? What was happening with the trany to begin with (if he fixed it). Selinoids may be worn and he didn't replace all of them - this is one cause of hard shifting after the computer realises the trany is slipping... but if detects slippage right away then could it be computer/programming related? Not sure and i'm no expert but mine has been hard shifting for sometime and need new one (compuer reports selinoid problem and slipping).
#3 of 5 Re: 2000 Montana cuts out [kennie]
Mar 05, 2009 (1:25 pm)
My husband told me that they replaced only componets in the tranny not rebuilt. We have 149,000 miles and it was shifting hard and slipping and shuttering, we would turn the key let it cycle then start for the past yr but it was getting to where it did not matter about that and shifted hard all the time. So we took it in and it came up with code 1811.
we dropped it off again to the mechanic and he said no codes at all on computer. On our way home it shifted hard again in to 2nd gear. The computer that was replaced was a remanufactured one with a 18,000 mile 1 yr warranty as well.
I know the PCM was replaced on the tranny.
The mechanic said that it drove fine for them. But we only had it back 2 days and it also cut out 4 times. We may take it to GM to evaluate.
#4 of 5 Re: 2000 Montana cuts out [cbish]
Mar 05, 2009 (1:46 pm)
Whoever did the work should ABSOLUTELY warrnty it... don't back off on this point - these guys are professionals so they should be accountable for the work they do. If it is doing the same thing then it is likely trany-base. I am not a verhicle expert but I do understand the probability of origin of error and I think I am right in saying that the PCM is not in the trany... it is the PCM for the vehicle including the tranny. I do not know all the reasons for tranny slipping but the 3 things you experience is often related to the presure selinoids in the trany which there are a few. I understand this from readings over the past year or more b/c mine is doing the same thing but not all the time yet. I believe there is a sensor that detects trany slippage and the PCM (to protect the trany) goes into like a trany protect mode that enables the presure control selinoids (one or more) to all trany fluid through a FULL FORCE to minimise any slippage that occurs between the plates to keep them from burning out (which is really bad b/c once burnt you whooped). At full force, this is why you get hard shifting I believe.. the shimmering that you feel I would think is the tranny slipping when changing gears. Now what I have read is that the presure selinoids often wear out causing them not to provide the correct presure in order for proper shifting - just the right presure to not cause slipping. What happens when they wear out is that they don't do their job and the computer (PCM) and sensor detect slipping in the trany and after a certain number of times it goes into trany protect mode described above. There are pictures of these selinoids on the internet that show the wear... if I find them i'll post them but I don't think I kept them. It could be that the selinoid causing the problem was not fixed, leaking or damaged and therefore using the PCM reset proceedures that we are all using no longer works and it goes into the safty mode or the selinoid is so bad that it causes hard shifting right away. Then again, I AM NOT AN EXPERT ON THIS and only using common sense and taking what I have read and understood by talking to dealership and a couple transmission shops. When I went to my local trany shop and started asking him questions he pointed to the wall and said "see that trany - that is a montana trany rebuilt ready to install in your vehicle for $2800 - it makes no sence whatso ever taking your tranny off and trying to fix it b/c it will cost you the same in the end and not replacing everything is just going to potentially cause you and I more work in the end. We will not fix your trany - we'll replace it with one that has had a complete component replacement and reconditioning and take yours and do exactly the same for the next guy that comes in the door". That said, whoever did the work for you they should be responsible for fixing the problem in my mind... just b/c there are no codes that makes me think there is something going on that I don't understand either... curious what happens please continue to post !!!! ... and good luck, don't back down.