2015 X5 S Faulty Transmission Module 421342

[Joelskim1]

Does anyone have any input on this error code. My normal mechanic will not open the transmission case and referred me to a mechanic who wants to do a rebuild sight unseen based on the fact that the car will not go into reverse at all.

The mechanic had to reset the transmission to make it work only for it to go back into a malfunction light on the dash.

Quoted 7k for a new transmission. Any feedback or thoughts would be appreciated. No problems with the transmission prior to this happening. 120k miles.

Thanks in advance all!

[RED_Y_]

Did you service tranny at all?

[Joelskim1]

No. Just driving like normal and accelerated and had a hesitation while accelerating and the drivetrain malfunction light came on. Car would not go into gear after and had to have it towed.

My mechanic recoded the transmission and got it to go into gear but no reverse and it continues to show malfunction error.

[RED_Y_]

Well before going into the swap I would at least try to pull error codes, see what they are pointing to and go from there.

[Joelskim1]

Appreciate the reply.

[Chilled]

If your not mechanically inclined yourself, take it to a transmission/specialist shop. There are allot of steps before you just go replacing a transmission simply because it wont go into a gear.

There are things you could try but, you have to be willing to start pulling things apart a bit.

Have a read through the 8HP70 training manual.
https://akpphelp.ru/images/contents/...tvo_manual.pdf

If even with error your getting, its going into P/N/D, but cant get into R. It could be simply your solenoid D is having issues or one of the valve is gunked up and stuck.


Whilst driving, can you get into 4th gear?

[Joelskim1]

Thank you for the info. I cannot drive it long enough to get up to speed. My mechanic had to recode the transmission as it goes into drivetrain malfunction mode quickly. At that point it does not go into gear at all and they reset to try to move the suv.

[RED_Y_]

There is no such a procedure to "recode the transmission" he probably just erased codes. Take it to the tranny shop, no just local mechanic on the block. Make them read codes and start with servicing transmission. If it was never serviced in 120K miles there is a good chance it just needs a decent service and adaptations.

[Joelskim1]

Not what I wanted to hear. Trying to come up with a plan. If you don t mind me asking what was the cost for the new transmission and how many miles when yours failed? I was quoted 7000 us dollars.

[Joelskim1]

I appreciate the links and info so much. I do have an s35i same as your then correct? Trying to prepare a plan and all of this info has been a great starting point. Did you end up keeping your x5 or selling after the swap. The repair costs are high. Air bag suspension went last year thankfully under warranty but the bill at the dealer (higher of course) was $6000. I look at the yearly cost to operate and this x5 is not looking favorable. Still hard to believe babying this car that the transmission would go. I tow trailers and fully expect truck transmissions to go but not on this suv.

[jfandl]

Originally Posted by Joelskim1

No. Just driving like normal and accelerated and had a hesitation while accelerating and the drivetrain malfunction light came on. Car would not go into gear after and had to have it towed.

My mechanic recoded the transmission and got it to go into gear but no reverse and it continues to show malfunction error.

You have to understand how the transmission works which a decent transmission shop should. With no service on maintenance, it's possible you have a blocked filter, gummed up fluid or something that is preventing the fluid from getting through the valve body properly. It could be a stuck ball in the body, it could be the filter being blocked, it could be a blocked path in one or more of the fluid paths in the valve body or it could be a bad solenoid. There 8 solenoids on the valve body if memory serves me correct so one gear may not work but others might since they have multiple solenoids.

In short, it may not be too terrible, just get it to a shop that has experience with 8HP transmissions.

Note: If you replace the 8HP45 or 8HP70 with an 8HP50 or 8HP75, you cannot swap the solenoids or electronics - they are physically different.

[Joelskim1]

I appreciate the info. I am not sold on the fact that at 120k the transmission failed. SUV was driven very carefully and never abused. Replaced transmission. $5800 later drives again but will never own another bmw out of warranty. I’ve never had a transmission fail In 30 years of driving. Love the car and safety features but repair costs and mechanics seem to just take advantage of owners.

[agnesgam]

Originally Posted by Joelskim1

I appreciate the info. I am not sold on the fact that at 120k the transmission failed. SUV was driven very carefully and never abused. Replaced transmission. $5800 later drives again but will never own another bmw out of warranty. I’ve never had a transmission fail In 30 years of driving. Love the car and safety features but repair costs and mechanics seem to just take advantage of owners.

What is the end of the story please? My x6 has 60k and having similar issue

[m4forum]

I agree that 120k is too short for transmission failure. It should last the vehicle life.
Have you ever replaced oil? Recommendation is 100k by ZF.
Could be as simple as solenoid or electronics which doesnt require the transmission to be replaced only parts.
I dont see the transmission to fail mechanniclly like clutch or gears.
Had 120k failure in the past. Had to replace the elctronics. Got used tranny $500 from junk yard. The hard part is to program the vin on ecu. Found person on ebay that does that.