Re: Brake sensor testing

["Russ Maki" <rinard@xxxxxxxxxx>]

Will -- the first thing to check is the ABS relay. There's a fusible link
inside the relay that burns out if the car is jump-started improperly. It's
clipped to a support just above the ABS computer, behind the dash on the
driver's side. Remove the knee bolster, look for a large aluminum box just
to the left of the steering column and feel around on top of it. You'll find
the relay in short order.

The relay can be repaired, BTW -- take the housing off and you'll see where
the fuse wire has parted. Solder in a replacement fuse wire from Radio
Shack.


Russ


> From: "Will Hartje" <WHartje@domain.elided>
> Subject: Brake sensor testing
>
> My 1990 E30 325i has the brake sensor light on permanently. The pads are
> good and I have tested the continuity of the sensors themselves and they
are
> good also.
>
> How should I troubleshoot the rest of the circuitry? What sort of voltage
> levels should I be looking for, and does this system have any known
failure
> points that I should check for?
>
> Any help would be appreciated
>
> Regards,
>
> Will Hartje

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