I have an 84 733i, and I've been working on fixing several of the problems in the car. One of the last ones that immediately concern me isthe temperature gauge, which doesn't budge. The sender is good, the indicator is good (passed some current through it,) and I can "see" the sender from the connector going to the instrument panel, so there is a loss of the signal inside the panel. The wiring diagram shows a component in between the connector and the indicator, (forgot exactly what it was called, and the book is out in the car right now) so I would like to check that out. I assume that it's the chip where the signal is disappearing, and was wondering if by chance a reset might correct the situation. Which leads me to ask: what exactly is the reset tool mentioned in the books, and how is it used?