I have searched and searched to not really find much help here. I found one video with the same code and it ended up being the mechatronics adaptor.

Heres my situation:

Bought the car last friday with no issues drove it home 100 miles with no issues but that same night on my way home from dinner the issue started.

The issue:

every gear 1,2,3,4 shifts fine and 6,5,4,3,2,1 shifts perfectly fine but 4,5 flares then thumps into gear with a trans malfunction code. INPA reads as follows: 4f8a 4-5 last error 101,106 miles ( what the car has ) tempature 78C

the trans doesnt seem to be overheating as it doesnt reach 95 in INPA

Is my whole box screwed, a mechatronics issue, or the many different sleeves and adaptor causing the issue?

what is my best route of action to diagnose?

How can i test mechatronics in INPA?

I hope my box isnt toast and its something simple.

 

What year and model e60? Do you have any service records? Has the transmission ever been serviced?

Also mandatory reading: So You Just Bought an E60 - Bimmerfest - BMW Forums

 

Sorry i thought i had it in my info its a 528xi 08. i have a decent knowledge of BMWs i have owned many including a 535i that i had 60k trouble free miles with and i had it on e85+fbo with no trans issues ever. Once it gets into 5th there is no slipping it never free revs reverse works perfectly its just between that 4-5 shift there is an issue.

 

 

sorry for not replying sooner. I did fix the issue it required valve body replacement. I bought a donor trans for $300 removed it’s valve body put it in my car new sealing sleeves and electrical connector. Reset adaptations and was good As new.