[F10prodigy]

2011 F10

was driving a couple weeks back, D on shifter started to blink i immediately park the car and turn it off.. i turn it back on car wont get out of P.

i have the car towed back to my lot and proceed to try and diagnose.
i get a P2721 code - Pressure Control Solenoid D Control Circuit High


i had a brand new zf8 pan/filter and trans oil i threw in the car. old oil was pretty dark pan had a lot of sludge but nothing super alarming.

trans still wont go back into gear.

i did notice that the gear selector it self ( i removed it) gets extremally hot on the passenger side (it has a metal plate) not sure if anyone has experienced it or not but do these go bad?

any advice would be great thanks.

[Breach]

When did you change the fluid and the filter, was it recently? Possible that - either they didn't fill the oil properly (or used the wrong oil), you have failing solenoids or the mechanotronic is blocked - sometimes happens after an oil change. I'd check oil level first - it gets more expensive if it's not that :-)

[F10prodigy]

thank you!

oil replaced post lock up trans took about 5L of fluid.
not much was in the trans close to 3L, it was rough looking very dark and sludgy.

my anxiety went through the roof i probably wasn't making too much sense of the issue nor how i was explaining it.

i keep getting the P2721 code on my obd scanner, i just got ista though so im gonna run it through and see what comes up but im leaning more toward bad mech. it was in pending/perm codes as well and it comes back as soon as i clear it.

i have a replacement tranny in sight for pretty cheap, im also super close to FCP's warehouse location and they have been holding me down with parts. just trying to figure out what route im taking with this car.

ill keep updating this thread for anyone else who may be in the same boat now or in the future.
*** service your trans! its cheap and not that hard.. and sure as hell beats getting to where im at ***

[Hoa]

Most likely just need to replace the valve body. Transmission is probably still ok

[F10prodigy]

Redacting my last post:

code 420012 is permanent
solenoid has to be replaced.

ordering the valve body.

[BuiltnBoostedZ]

be very cautious changing the trans fluid. BMW calls the fluid "lifetime". If you haven't changed it regularly early on in its life, you shouldn't change it at all. The detergents in the newly changed oil will break lose all that shit the sludge and old oil is holding together if your mileage is super high (120k plus). Should have just changed what the code told you too. Let us know how it goes. Most if the time the trans is toast after running it on new oil for a few months. All depends on your mileage.

Having said that, I change my fluid every 30k miles. Pain in the ass bc you judge full by the stream that comes out. And not all the fluid comes out like it should as you have seen with the sludge.

[ezaircon4jc]

Originally Posted by BuiltnBoostedZ

be very cautious changing the trans fluid. BMW calls the fluid "lifetime". If you haven't changed it regularly early on in its life, you shouldn't change it at all. The detergents in the newly changed oil will break lose all that shit the sludge and old oil is holding together if your mileage is super high (120k plus). Should have just changed what the code told you too. Let us know how it goes. Most if the time the trans is toast after running it on new oil for a few months. All depends on your mileage.

Having said that, I change my fluid every 30k miles. Pain in the ass bc you judge full by the stream that comes out. And not all the fluid comes out like it should as you have seen with the sludge.

More wives' tale. If there is sludge the filter will catch it. Would you not change your engine oil? Brake fluid? Coolant?

[F10prodigy]

cleared out the codes
(55 codes on ista first time around)

7 codes left now
420012 - now changed "existent" from permanent to unkown.

ordered the valves today, once they get in ill get to replacing them and update once its done.

[F10prodigy]

anyone have a clue where to order a kit for zf8's?

ebay has 4 listings in the US. none are original it seems, safe?
Fcp, Ecs, AZ, and etc do not carry for zf8 only zf6.

[F10prodigy]

installed a used mechatronics unit

new issue im having is programming/coding the new unit to the car.

[F10prodigy]

Car is back on the road, little recap for anyone experiencing similar issues:

-car gave a solenoid D trouble code.
-wouldnt clear via ista
-had to replace the valve bodys.
-none available that were oem online (fcp, ecs, anywehre else)
-purchased a low milage transmission
-removed the mechatronics unit
-installed the whole unit
-fcp is the only place near me that carries Liqui moly 1800 (zf lifeguard also not available anywhere near me)
-got that and filled up the transmission only to find out there was some coding issues due to not switching -out the tcm
-had to drop the whole unit again
-replaced the mechatronics
-filled the transmission back up
-cleared the codes via ista
-car engaged gears
-double check everything and made sure transmission fluid level was good.

going to run this oil for a few miles then change it again for safe measure.

i want to thank everyone who gave me advice on here whole heartedly.

[OnlyGerman]

Originally Posted by BuiltnBoostedZ

be very cautious changing the trans fluid. BMW calls the fluid "lifetime". If you haven't changed it regularly early on in its life, you shouldn't change it at all. The detergents in the newly changed oil will break lose all that shit the sludge and old oil is holding together if your mileage is super high (120k plus). Should have just changed what the code told you too. Let us know how it goes. Most if the time the trans is toast after running it on new oil for a few months. All depends on your mileage.

Having said that, I change my fluid every 30k miles. Pain in the ass bc you judge full by the stream that comes out. And not all the fluid comes out like it should as you have seen with the sludge.

I would say if no history, and under 100k, still safe for drain and refill. My Indy said after 150k be risky.

[RH-27]

Originally Posted by OnlyGerman

I would say if no history, and under 100k, still safe for drain and refill. My Indy said after 150k be risky.

My F10 530D is on 118k miles and no history of the transmission oil service.

I'm planning on getting it done very soon from a ZF workshop.

It's not giving any problems at all, still smooth as silk when fully warmed up but ZF recommend every 60k miles so its well overdue.