Th3_ghost

Hi everyone,

I have bmw 530i from 2004 with M54 engine and ZF 6HP19 transmission. Six months ago my transmission started to go into limp mode when I press gas pedal really hard. At first I observed error code 4F8A Ratio Monitoring, gearshift 4-5 and after ignition restart, the issue disappers. After some time I had again such issue while cruise control was on and there was no hard acceleration, only keep up current speed, then another error code appears - 4F85-Ratio Monitoring Clutch E So I had changed all plastic adapters, sealing sleeves, everything inside transmission was inspected and looks fine, there was no uneven worn clutch packs but almost all O-rings inside were really bad including mechatronic plate rubber, so every rubber seals were changed with new. I had changed the oil with a new one(ZF Lifeguard 6). Before test drive I had reset transmission adaptations and goes into test drive where I pushed car really hard and there was no anny issues, the temperature of oil was arround 88 degrees Celsius. On other day I was traveling with the car for 300 kilometres and around 100th kilometer when I tried to push gas pedal harder, downshift 1-2 gears and accelerate really well and after when I proceed to release gas pedal, then rpms goes higher and transmission goes again into limp mode and error code was only 4F8A Ratio Monitoring

So my question is why after first try I didn't observe this issue? Transmission temperature looks okay always when error code appears(around 88 degrees Celsius). It looks like this issue is not consistent. Is it possible this issue to be software issue and software update to be required for EGS module?

Besides of this issue, the transmission change gears really smooth before and after servicing of transmission.

habbyguy

Did the problem start after doing the Mechatronics renewal, or did it happen before?

Th3_ghost

The problem happend before doing any maintenance of the transmission. Previous owner did change the oil 2 years and around 20K kilometres before i bought the car.

habbyguy

I'd make very certain that the level of the fluid is correct, by following the very specific process for topping off the fluid (car level, transmission fluid at 40°C, shift through the gears slowly a few times, fill until fluid is dribbling out fill port).

Beyond that, the ratio monitoring issues sure sound like slipping clutches. I hope not - these transmissions are VERY robust, but a slipping clutch is really the end of the transmission (requiring a total rebuild or replacement).

If you can put the car in a manual gear (so it doesn't shift automatically) and you can force it to slip by applying more accelerator, I'd say that you have a bad clutch in the transmission.

seanjordan20

We're the solenoids tested? I would first check the fluid level. How much fluid was put back in during your service. Should of been around 6.5L

Th3_ghost

The oil from the transmission during change of O-rings was drained out fully including oil cooler line and torque converter. We put around 7.5 liters oil after that. Some documents says that the transmission should have around 9-10 liters oil but I couldn't anymore because it was dripping hard from filling plug. Unfortunately solenoids weren't tested but if the issue could be caused due to solenoids, why this issue doesn't occur always when I tried to accelerate harder? I suppose that if the issue is something related with mechanical parts, it will be easily reproduced.

seanjordan20

You only got 7.5L of fluid with the TC drained. That is your issue you need to at least get 2L more in the transmission. You followed the fill procedure correctly. If I remember correctly I thought you don't put an empty TC back into a transmission. I don't know maybe thats something else I've worked on. Either way you're missing fluid.

habbyguy

I'm betting the fill process wasn't done properly (many don't, and end up with problems).

Did you follow the process I outlined in my previous post?

y0itzflip

its probably low fluid. I had that issue the first time I did mine. no matter how much I tried I kept filling it wrong (not enough) on the floor. got it on a lift and tried again and was able to get it goin.

also I would change the solenoids next time