I'm having a problem with getting my tranmission repaired. The tranmission fault light came on my independent BMW mechanic diagnosed transmission slip 048 code. He gave me 2 choices, replace for with a rebuilt unit at about $4500 or sub-out the work to a transmission shop to rebuild it for $3000 with a 3 year warranty. I chose the latter because it seemed like the better deal. But the transmission light came on again a week later with the same fault code. They took the tranny apart again and couldn't find the problem, they tried changing the torque converter but it still set off the code. They also updated the Transmission Control module but still the problem persists. Any other suggestions? I've done an internet search on this issue and someone mentioned a possible voltage problem. How can this be related to the transmission? Thanks.