> Just curious... how many speed sensors does the e39 have? I thought there
> was just one near the right rear wheel...
4 - one for each wheel.
I suspect you have no idea how ABS/DSC works right? It compares wheel
speeds. If it finds one wheel turning when other are slipping and the
brakes are in use - it modulates the slipping ones using ABS. If it
determines one of the rear wheels is turning faster than the other
wheels in the car - it knows that wheel is slipping and it reduces speed
on that wheel (with the throttle and brakes.) On later models it gets
even more powerful, comparing the yaw angle of the car (rotation around
it's axis) the G forces and the turned angle of the steering wheel to
determine if the car is going where the driver wants it to go. If not -
it uses dynamic braking on the wheels - individually - to correct.
It couldn't do this without 4 sensors right?
> Also, the speed sensor is integrated with the ABS module, so you replaced
> the whole module, right?
No it isn't. Wheel speed sensors are located (ta-da!) the wheels.
> Thanks,
> Pete
Pete - 07 Mar 2007 21:57 GMT
> 4 - one for each wheel.
OK, I guess I was not clear in my question. What I meant to ask was how
many sensors feed data into the speedometer in the dashboard?
>> Also, the speed sensor is integrated with the ABS module, so you replaced
>> the whole module, right?
>
> No it isn't. Wheel speed sensors are located (ta-da!) the wheels.
Again, I was asking about the speed sensor that feeds the speedometer, not
the ones that are used for ABS/DSC. Sorry for the confusion.
Pete
Bill - 07 Mar 2007 22:11 GMT
It's in the rear differential. It has a wire hooked to it and can be seen
easily if you look under the rear of the car.
> > 4 - one for each wheel.
>
[quoted text clipped - 10 lines]
>
> Pete
admin - 09 Mar 2007 16:33 GMT
> It's in the rear differential. It has a wire hooked to it and can be seen
> easily if you look under the rear of the car.
Not any more - they gave that up with the E34 series.
The ABS sensors are used to determine speed - everything is fed
through the ABS/DSC module - including the signal to the
speedometer.
What the original poster apparently doesn't want to accept
is that the damn modules GO BAD... and give all the symptoms
he's seeing.
You can drag a cow to water..