Trans repairs vs trans service

[killcrap]

Originally Posted by CharlieHustleX5

You personally have not been in the car and witnessed the vehicle's reaction to driving with the TCU connected and disconnected right? Have they cleared all adaptations on the TCU and tried to see what the result was? What codes did they transmit back and forth? Would they even tell you?

I'm not saying your tech has done a bad job or undermining his abilities. I'm curious to know of the answers. Like I said, most of the time thats what they're prompted to do to save time on diagnosis and to get the car back into your hands faster. Having a CPO vehicle is definitely great and the dealer is taking care of the issue.

The EGS is the Transmission Control Unit, and BMW no longer has them in the sense of external control unit on new Series vehicles SOP beginning 2002 excluding Z4/X3 Its now the mechatronik Concept. Where the valvebody and control unit is together.

Nobody at BMW be it Klaus or Carl Barbara(i wouldnt expect you to know who they are yet) will EVER tell you ever to drive the car with the mechatronik disconnected. They would however tell you to disconect the VTG motor to stop the actuator from applying the clutch. So that is probably what they are talking about.

Neither will tell you to clear the adaptations to see what it does. The only time you should clear adaptations/reset learning functions is after programming the EGS, or after clearing the DME/DDE adaptations. Reset mechatronik is only for replacing it.


Speaking from experience, and not Step BMW Factory Training(haha), If the valvebody were bad(seals, checkballs, solenoids, etc) the entire mechatronik would be replaced. And i have never had a fault code stored for any transmission complaint in which the fix was to replace the Transmission.

Here are the only type of complaints ive come across relating to the transmission on X5 Facelift V8 when being repaired by BMW underwarranty

Transmission Fluid Leak - Mechatroniks Sealing Sleeve Leaking

Vehicle feels like being rear ended when coming to a stop. - Transmission Replacement/Transfercase Failure

Transmission has a harsh 2-1 downshift at times - Software error in EGS/Transfercase failure

Transmission is shifting back and forth at 35-40mph. Pendulum shifting due to faulty Mechatroniks.

Trans Fail Safe Warning is on - Ignition Switch or Alternator

4x4 Lamp Was Illuminated - Sluggush VTG motor operation(ambient temperature freezing conditions)

Transmission upshifts and downshifts harshly - Fluid Leak, FC4F5/4F81/Transmission Replacement/ Transfercase failure

Transmission makes wooping noises at idle - Perform Double Flush Procedure.