Intermittent no crank followed by Trans. Prog. Failure

[DrCharles]

For some time, my E38 has had an electrical gremlin - you turn the key to Start and absolutely nothing happens. No click, no crank. Dash lights look like the key was never turned past On. After a few tries, the car would always crank and start... followed by TRANS PROG FAIL message. And indeed the trans was at full pressure ("bump" on shifting to R or D) and locked in 4th.

Shut off, wait 20-30 sec and restart, and everything behaves normally. Until the next time it happens!

After some reading, and remembering that the cruise control sometimes stops working at random I figured my ignition switch was the cause, and decided to replace it today. This write-up: http://www.bimmerboard.com/forums/posts/244045/ is perfect, and it probably took me half an hour.

BUT when I tried to start the car with the new switch the first time - Exact same symptoms still there

So. Now where should I be looking? Battery is recent, running voltage OK. I suspect a relay that is not engaging when the Start signal goes to it, but how would that confuse the transmission controller after a crank/start? Same if it's yet another EWS-related problem...


thanks
Charles