Electronic transmission control

It means it is time to go to a M/B trained tech. I hope you noticed I didn't say the dealer. There are shops that specialize in M/B only.

first i would see if the trans ecu is full of ATF MB's of your vintage had 'issues' with ATF 'wicking' up through the wiring from trans to ECU.. ive fixed many 'faulty' ecus simply br draining the oil (after simple dissasembly) cleaning the printed circuit board with BRAKE wash (mild degreaser) then cutting a small drain hole in the plastic housing before reassembling it it sounds harder than it actually is.. by the way ive NEVER seen one of these ECU's fail .i worked as master tech at dealership from 2000 to 2008

The brake light switch on the pedal is a common cause for this.