I was looking online for possible causes to this issue on my 06 Cooper S Automatic and possibly a good recommendation on what to look into. I can tell you for one I WILL NOT BE TAKING IT TO THE DEALER soo please spare the "take it to dealer" comments lol. Below are the details:

Model: 2006 Cooper S Checkmate Edition
Transmission: Aisin 6 Spd Auto (NON CVT) GAF21WA-TANA
Mileage: 123k

I was driving the car one day and decided to try the paddle shifters for a change since I had the car almost a year and never really messed with them. I am familiar with paddle shifters as I have had many vehicles with them. So, I began to drive and as i shifter properly into 3rd gear, I felt a "violent jerk" into 3rd gear which was unusual and felt a loss power immediately. I pulled over, turned off the car and drove off again on normal drive without paddle shifter usage and the car drove fine until it reached 3rd gear, it jerked into 3rd and would not shift into 4th gear or downshift into 2nd on its own. When I slowed down to a stop, I noticed the the Triangle +! , CEL and EML lights all come on and when driving off again the car was as if it was slipping and trying to catch up to speed (almost like when a clutch is slipping and your car slowly builds up speed). Once I caught speed, it would not go past 3rd at all or downshift to 2nd when I slowed down....UNTIL, I turned the car off and on again it would drive fine as long as I did not go into 3rd, otherwise it would get stuck there.

If i drive from a standstill as say into a clear freeway, the car will go thru 1, 2 normal and when going into 3rd it jerks but still goes into 4, 5 and 6th fine UNTIL I once again slow down It has gotten stuck on 3rd and the process of shutting off and on continues in order for me to get it out of the "stuck" mode.

I have googled endless scenarios and read about the possible solenoids being bad, valve body issues, trans adaptation procedures and even took it to get diagnosed at a local INDIE mechanic shop which the tech could not give me a definite answer and said it could be the trans itself and would cost $5k to replace (more than the car is worth) or that due to a power steering leak that was current, fluid may have seeped into the connectors causing an electrical failure but he then checked the connectors and said they were not moist. He was also stumped and said the part where he felt it was an electrical issue was due to the fact that turning off the car and back on would reset the transmission computer which if it was s trans fault, it would be stuck in 3rd for good.

There you have it, good 'ol lengthy post....Any help or direction would be GREATLY appreciated!!!!

 

I am clueless about the automatic transmissions in these cars, but here's a few pages from a book that I have...






If it is impossible to troubleshoot and diagnose, one option would be to buy a used unit from a junkyard and swap it out.

https://www.car-part.com/

A good resource where you can look sorted to price, mileage, or distance.

 

Did the shop tell you what were the CEL codes? Might not be the transmission. Bottom line it’s going to need to be diagnosed in person.

 

I can confirm that limp mode will put you in 3rd and leave it there. Mine had a wire break on the harness.
bad solenoid and valve body will cause harsh and delayed shifts for second and third and is very common. Usually worse once the fluid is warm.
go to a trans specialist. This unit is shared with VWs and Saab so is fairly well understood. A new valve body may fix it. Should be under $1500.

 

Sounds like you may need a fluid and filter change .... you could possibly have a failing solenoid(s)... try dropping abit of fluid and check if you see excessive contamination in it which would be clutchpack material and it would start to smell like burning rubber almost...
if you need , I actually have a fill tool that screws into the pan so you can pump fluid on in , just toss me 5$ for shipping abd ille send it to you if you'd want it.. I used it wgen I was working on an automatic transmission also..

 

Wow, you have provided more info than even the shops and other forums have in 1 post! Thanks bro.
BTW, do you know if swapping out solenoids or whole tranny will require the re-adaptation procedure to be done to the car? I feel confident in swapping out solenoids but some videos on youtube say you have to do the adaptation procedure which living in SoCal and its traffic, I am unable to to do since it requires to coast at speeds without stopping.

 

Yes, I have a scanner and said "incorrect gear ratio" on gears 1, 2 and 3 and sometimes only on 1 or 3 etc.

 

I would really appreciate it. DM me your info and ill send it.

 

I set up accounts on Mini2 and minicooperforums a year ago and never had even 1 reply but over 200 views on each site. Here, I have had more help and insight than even in person, So just want to extend my gratitude to all who are taking the time to give me their insight. Please continue to do so.

BTW, I am strongly leaning to do a trans filter, oil and solenoids change at this point since its about $400 total and the cheapest option of all the rest. I figured, Id hate to do the trans filter/oil change and then have to go back in there if it doesn't help.

Any of you local to SoCal? OC?

 

If you get inpa. You can reset your transmission adaptation.

 

Be careful with aftermarket solenoids. I heard not so great results. There is a video on YouTube that has a guy refurbishing the existing solenoids. Most of the time for a solenoid to fail is due to contamination buildup. This in turn causes the solenoids to stick. Check video link

 

I have a 2005 S with the same transmission. There is an older thread - search for it. - it is about how to drain and fill with new fluid. I did that - but back in 1015 @ 110k, I had the valve body rebuilt by a transmission shop in New Jersey. Now @ 153k. You need a reader that gives you detailed transmission codes. I think you really need a good transmission shop. It sounds like this is above your level.

 

Thanks for the info. I actually am considering getting them from what appears to be a reputable solenoid provider called wolfsburg tuning. They seem to even be on Amazon but at about 50 more than their website. I will def check the video out though. BTW, where could one get the INPA software?

 

Having dealt early on with the automatic trans in our 05 S, the issue usually isn't the solenoids themselves. The issue is that Aisin (transmission manufacturer) decided to use hardened steel valves in an aluminum valve body. Over time, the valves will wear away the aluminum bores and cause all manner of shift issues. The only solution is to replace the valve body. A new (reman) valve body will have hardened steel sleeves inserted into the bores as per SONNAX to eliminate the issue.

Your issue though sounds more complicated. There is a steel sleeve within the transmission that regulates fluid flow to the K2 clutch which controls 4th, 5th, and 6th. That sleeve may have rotated partially and is restricting fluid flow. The only solution there is to pull the unit and rebuild it.

All that aside, start with changing the fluid first. I'm sure the fluid you get out will be completely black and burnt. It'll probably take 3-5 changes to get most of the fluid out of the unit. Don't worry about buying premium fluid for this part as you'll simply be dumping it after driving a few miles. Toyota T-IV transmission fluid is a great alternative to use for this process. If the shift quality improves after you've gone through 12 quarts, start swapping in premium fluid. As for the filter, since this is possibly the first ever fluid change, go ahead and replace it. That'll give you the chance to see the wiring and make sure nothing has been nicked and possibly shorting out.

 

replace the whole valvebody , the solenoids wear down the valvebody abd they dont seal , thats what causes the slipping.. i just recently did a valvebody swap I can link my progress thread to you to.. I also pm you to get you that fill tool.
I bought a rebuild valvebody for like 300$ only and it's a very straitforward removal of the old one and install of new one..
I'd HIGHLY suggest doing a whole valvebody vs just replacing a valve and to put it all backtogether and it still slip because of a worn valvebody or you replaced the wrong valve..

 

https://www.northamericanmotoring.co...fo-needed.html

 

This is my opinion too, based on experience and lots of user postings.
The sleeve rotating is a thing too, hopefully it's not that. I think a trans specialist is worth the spend.