When I look that up online I get the same rationale. BUT, my $300 engine scanner says exactly "P1738 Primary Speed Sensor"

I have an alldata account, but BMW keeps their stuff proprietery!! Grrr!!

My truck is in trans failsafe mode, I need to figure out what the reall problem is and replace it.

I am going to go out and try to check the wiring harnedd connections, maybe there is corrosion, I have heard of that before...