E46 Electronic Transmission Control Module Problem

I've run into this a couple of times before with other vehicle makes...the first, and least expensive, step to take is to check your automatic transmission fluid level. There has to be a sufficient amount of fluid in the transmission case to provide adequate pressure...if not, the symtoms you describe will occur.

Ignore that. You've got mechanical problems in the form of a slipping clutch - not electronic ones. And even if an electronics fault had initially cause the clutch to slip it's now toast.

If the electronics discover a problem, it puts the box into limp home mode. This is very similar to snow mode (in slightly earlier switch mode boxes). Whilst this results in poor performance* the symptoms you describe sound like you have worn out a band and / or the fluid has run out, so it does sound expensive.

• a neighbour offered me a lift one day when my car was having a service. Whilst she dropped something off I noticed that she had accidentally engaged snow mode (a manual setting on her Renault). I switched it off, and asked her how the car felt. "So much more responsive - what have you done?"

Well, after talking to one BMW dealership and a second BMW independent repair shop......the transmission needs to be replaced. I considered the 'fix it' approach versus the 'replace it' approach and am worried that if I dump $2000 into this thing for a fix it might crap out again in 6 months. But the replace option gives me a 2 year unlimited mileage warranty from BMW. I contacted BMW North America and pleaded my case. They're giving me a 50% discount on a new transmission (car is a 2002 with 82,000 miles....out of warranty). I'll still spend between $2000 and $3000 but as of yesterday I was looking at $4000 to $5000. Love those Steptronics, but I guess they do break. Tom