ABS Failure

[Brad Hogg <roadhogg@xxxxxxx>]

I found a schematic in one of my service manuals along with diagrams showing
me where various components are located.

http://imperial.point2this.com/misc/CarStuff/ABS/ABS.jpg
http://imperial.point2this.com/misc/CarStuff/ABS/Schematic.jpg

I tested the pump motor, the pump motor relay and all fuses.  Everything so
far tested fine.  I determined that the pump was not being turned on.  The
question then was, "What is supposed to turn the pump on?"  Looking at the
schematic, there is only one thing that will turn the pump on and that is
the "Dual Function Pressure Switch" located on the lower right portion of
the schematic.  I separated the "Switch/Transducer Connector (Black)" and
tested pins 1 and 10 for continuity to ground.  Pin 10 gave me no continuity
to ground and pin 1 gave me a very slight continuity to ground.

I believe the purpose of this switch is to turn the pump on when the
accumulator pressure goes low.  The switch is also part of the self test
system when the key is first turned to the ON position.  The pump is
supposed to run at that point but it doesn't.

I've been advised to send the thing to my dealer because this may all be
covered under warranty.  I'll probably do that after I return from Rhody
days.  For today and tomorrow though, I'll be driving with manual brakes.

----- Original Message ----- 
From: <OTTODOCFACS@xxxxxxx>
To: <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Sunday, May 16, 2004 6:21 PM
Subject: Re: IML: ABS Failure


roadhogg, is your 90 a late build , on account of having bendix
abs system?
my 90 has the bosch abs system and was built jan or feb of 90.
i know some things on the bosch system but not too much on bendix.
if it is bosch i will try to help you .
i went thru a entire dissertation several months ago with another
club member who was having trouble with his bosch system.
if you would like i can look it up in the service manual for help.
let me know
frank