Bought a 2010 750Li with 131k miles knowing it has a bad transmission. First car wouldn't even go into gear. No fluid. I had mechanic change all the "mechatronics sleeves and refill with fresh fluid. Car now drives but it kicks you in the butt(on acceleration and deceleration) after a few shifts and goes into limp mode. My question is do I need a transmission or can I get away with just the valve body being rebuilt? I found a transmission I can pick up, but I have to make a decision while it's still available. Posting the Codes below. Bite the bullet on a Used Trans or go the cheaper route and re-do the valve body?  Your input and suggestions are appreciated.

 

CF1701 Message (All) For (EGS_EL,A-CAN, FA-CAN) From (GWS, A-CAN, FA-CAN) is missing 

1DB301 EGS, Signal Monitoring (Gear Information) Invalid Signal Content 

CF0400 Total malfunction of the CAN-Communication by line interruption 

400441 Ratio Monitoring Clutch E implausible 

400331 Clutch Monitoring 3-4 implausible 

401011 Collision backup measures with Equal Priority 

213901 Consumer Readuction: Active 

 

 

 

Morning Donald

Have you checked the loom for damage and the connectors for loose pins. Around the age of your car I read several reports of failed Mechatronc units so a new/rebuilt unit may well be the cure.

The trans you are considering may be in similar condition or going that way so ideally a test before buying may help but a used transmission will always be a gamble

For me I would get the Mechatronic unit checked and rebuilt by a Trans Specialist (or best by a ZF specialist) 

What condition was the sump in when you dropped it ? was there much debris were the magnets clean ? If the fluid was changed a few times by the previous owner trying to fix the issue chances are the Torque converter has been flushed fingers crossed they used the correct fluid.

BMW at this time stated Transmissions were "Sealed for Life" (BMW speak "life" was the end of their Warranty responsibility) ZF however recommend service every 60k to 80k 

Good Luck

Dave