Originally Posted by KyleB

That's hightly doubtful. A software update will likely do nothing for you. 4F85 is telling you that the E clutch slipped at some point. Hell, if you read it with INPA it will tell you what rpm it slipped at and the exact mileage when it happened. So I'm sorry to say but I'm pretty confident that mechanic is DEAD WRONG. 4F85 isn't a TCM failure, it's a specific fault code referencing a fault for a specific component, in this case it's for the E drum in the gearbox. By his logic, a check engine light for a cam position sensor means you need a new engine. That's nuts.

By new 'TCM' he wants to replace the valve body, which has the block, solenoids, and computer all integrated in one unit. Think of the transmission as two main components that get replaced; the mechatronic (valve body), or the entire transmission. Sounds to me like he's taking a shotgun blast approach. And $4K is ludicrous, considering a fully refurbished valve body can be had from ZF for around $1500. I'd love to know where the other $2500 is coming from. That's robbery.

You can drive the car nicely, but if you get 4F85 or any other 'slip' code again you definitely need to do something about it ASAP. clutch packs inside of an automatic transmission do not like to slip repeatedly (hence the christmas tree of warnings when it happens even once), and if you let it go too long you WILL be replacing that entire transmission.

Again, I can't guarantee that replacement solenoids will fix your problem, but they are a known weakness in this transmission, and replacement of them along with all of the related seals have resulted in a lot of people having successfully repaired transmissions. I'm pretty confident that if you went the same route I did you'd solve your problem.

If you do go that route make certain that you also replace the bridge seal, four sealing sleeves, and mechatronic sealing sleeve along with the solenoids. That $12 bridge seal will wreak havoc if it's worn, as will those four sealing sleeves. when I compared old to new, all four sleeves were noticeably shrunken, and the rubber portion of the bridge seal was worn and brittle. Proper pressures and fluid travel are vital to an automatic transmission.

Again, best of luck to you.

Originally Posted by ilham007

Mine is also a 04 530i with 105k on the cluster. I faced this like a lot of times even after chaging the transmission fluid from my dealer. I advice you to warm your car up properly before you decide to drive off. It works!

Originally Posted by frankgeo

Thanks Kyle, again you are a living BMW encyclopedia, 100 times better than a regular mechanic...that's what scares: I have to take it to a regular mechanic and not to you ...

I like the INPA approach so I could get all the detailed info instead of the random codes from my android app which could have happened 5 years ago for what I know...
Questions:
1) where can I get the INPA software (I saw the cables on amazon for about $20)
2) I just deleted the codes (I want to understand the frequency of the error since I bought the car 2 months ago and not sure if the codes had been there forever...) with my BMW android app. Will INPA still be able to retrieve past codes and miles when it failed or now I have to wait to happen again?

thanks again!

Originally Posted by e60eric

Kyle - Would you have the same diagnosis for the same symptoms but without a thrown code? I have a 2006 530i with 130k and I experience some very slow shifts between 2-3 and 3-4 under moderate accelerate, but I have never received an error code. A few times, there was a long delay between 3-4 followed by a very unpleasant slam into 4th. I recently drained and refilled the tranny fluid with a new filter/pan using your service thread (thank you!), but I did not venture into dropping the mechatronics and replacing the gaskets and seals. After the fluid/filter change I have not seen any improvement. Your opinion?

Originally Posted by KyleB

Did you reset adaptations after you replaced fluid? I'd start there.

Originally Posted by e60eric

I did. I've also driven more than 3,000 miles since the fluid change.


I should have also mentioned that I had the same problem before the fluid change. This was my main reason for changing the fluid. I was hoping to improve the overall shift quality with the new fluid and trying to get it to shift faster.

Originally Posted by KyleB

Thanks for the complement, although I would never call myself a BMW encyclopedia! I just happen to have traveled down the same path you find yourself on now.

You'll probably have to wait for it to happen again. Don't worry, if your car is like mine it'll happen soon enough, and likely while your wife is driving the car (I never saw it, she saw it about 10 times.)

As for cable/coding/software questions, I recommend signing up for a BMW coding forum. Your most up to date software versions and/or cable sources will be there. I got my stuff from a now defunct company.

You could always try to make friends with someone in your area that is experienced with coding and INPA use to help you too.

One last note: before you dive in head first and start replacing solenoids, bridge seals, etc, check the basics. make sure you don't have any visible leaks, and make sure your fluid level is correct. if you don't see leaks, fluid level is good, and youre still getting erratic shifting with 4F8X codes, I'd do what I did.

warming the car isn't going to help. think about it - you warm your car up every time you drive it. after about 10 minutes of use, your gearbox is up to operating temperature. if warming the car was the solution, I wouldn't be posting this because you never would have a had a problem to ask about

good luck!

Originally Posted by KyleB

How often do you experience this?

If you're not getting any logged errors I don't know there's much you can do. You're not the first person I've heard of to have a ZF gearbox with some mileage on it that shifts rough front time to time.