Re: Re: ABS activating at <5mph

["Smith, Kirby A" <kirby.a.smith@lmco.com>]

"Fred Munro" <munrof@isys.ca> wrote:
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- -----Original Message-----
From: Sherry & Chuck Clark <clark@rmi.net>

Well with all this talk of ABS, maybe someone will know
what's going on here. Car is a '91 200q. Just been lowered
with H&R springs. When coming to a complete stop at
speeds only below approx. 5 mph, the abs system kicks
in until the car has completely stopped. During normal
braking at anything above 5 mph, no abs activation at all.
This is only under normal braking. Abs still works fine
if you mash the pedal to the floor.Also, no
abs light on either. Why would the car do
this after having the springs installed? TIA for any help,

________________________
Chad;

    My '91 200q does this occasionally as I pull up to a stop. A
friend's
'87 5ktq had the same problem but his was quite frequent. He took his to
the
dealer and they couldn't resolve it. I think at the low speed one wheel
sensor is losing the signal and it assumes the wheel has stopped,
activating
the ABS. I might just be a problem with sensor position; maybe they got
pulled out a bit when your springs were installed?

HTH

Fred Munro
'91 200q  250k km
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My wife's 90q did that intermittently.  It turned out to be degraded
cogs on the left rear axel where the sensor picks up the speed.  There
was significant rust and corrosion.  You can find the bad one(s) with
some difficulty, but without disassembly, by looking at the sensor
signal while turning the tire by hand when on a lift or sequentially
after jacking up each corner.  Use an oscilloscope.  Look for signal
drop-outs or significantly different waveforms.   On my cars, the rear
sensor connectors are below the rear seat; the front's are on the shock
towers.

                .... Kirby   (Kirby A. Smith)
                              2 x 1988 90q
                          New Hampshire USA