Question Details

Could these errors be caused by low transmission oil ?

it only happens when i accelerate hard or want the car to kick down a gear 


Profile picture for user abusufyan

abusufyan  3 months ago

The 4F85 code is a bad transmission control module (located inside the transmission) according to BMW documentation. But I found a thread where this code was a result of a bushing failure on the input shaft. The entire shaft needs to be replaced for $500. (google 530i Limp Mode code 4F85)

Profile picture for user abusufyan

abusufyan  3 months ago

I have been driving benz product so I decided to go back and drive BMW product and just purchased a 2005 645 C1 with automatic transmission in excellent condition with only 69k miles and I had my car go into limp mode on the tranny When I drive IT hard ! But when I cruise I don't have any problems ? The error code is 4F8A (RATIO MONITORING.GEAR SHIFT 4-5 GEAR). I had my friend in his shop scan it. I even try to reset Ecu from tranny to relearn values and still error occurs when I drive hard. I purchased the car in a Dealer auction from my friend who is a dealer and I paid $14,200. I know why the previous owner trade in this beautiful car cause .. (Tranny Problem) . Its a convertible doesn't even have a scratches and it really is in mint condition that why I purchased it but I want to fix it now I don't mind getting a used tranny for about $1500 and doing the work myself I have done plenty in past but I really want to make sure it is the tranny or maybe if I get a ecu upgrade or replaced fluid ?? Any advice would be so helpful please... by the way the fluid is clean not burn and again I never have a problem if I just drive normal but if I floored it thats when I get the slipping problem on 4 and 5 gear and then it goes on limp mode instantly ! I have to shut down and restart engine and it runs fine ....

Profile picture for user abusufyan

abusufyan  3 months ago

DeenWEEKS have your issue been resolved?

Profile picture for user

Mully  1 month 2 weeks ago

I have a 2008 BMW X5 with 78000 miles on it i keep having this happening on this car. The code 4F85 clutch E,also 55C3,55D0,54C8. It goes into limp mode, i shut it off and restart works ok then happens again. Mechanic said needs new trans, what else can be checked. Could this be electrical. Please help

Profile picture for user Boki

Boki  1 month 1 week ago


Error 4F85 is quite common on ZF 6HP transmission, and it is caused by faulty E-clutch on the input shaft.  Other errors you have (55C3,55D0,54C8) are X-drive related, and are most probably caused by gearbox error.