seat heater (& mystery box)

[quk@isham-research.demon.co.uk (Phil Payne)]

In message <01bce4d4$a3caae20$3c34f8ce@server> "Lino M. Valadas" writes:

> >the back seat, activate locks and see if it hums.
> >>BTW, there is a black box (controller?) just inside the right end of
> >>the
> >>rear seat--outboard of the battery. It doesn't show up in the Bentley
> >>controller- layout diagram. Whazzit?
> >>

There is a _small_ black box with two wires attached under the rear seat of 
many post-1988 cars.  It's an accelerometer.
 
Many ABS systems use _only_ wheel sensors to determine if the vehicle is 
moving.  The problem is that if you're very unlucky and all of the wheels lock 
at once, the system has no input to tell it you're still moving.  It was 
possible to fool the system fitted in my 1987 Ford Granada this way, especially 
on wet ice - it was one of my favourite demonstrations.
 
Audi has fitted accelerometers since the late 1980s to overcome this problem.

-- 
 Phil Payne
 Committee Member, UK Audi [ur-]quattro Owners Club