Re: ABS

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

In message <79A9006C94BED111AA3900A0C9AB119C6A0AA1@OH_DAYTN_XCH03.stdreg.com> "Weeks, Chet" writes:

> I observe that the ANTILOCK OFF light is continuously on regardless of the
> state of the Antilock switch. The switch seems to work and the relay seems
> to work ( I can hear it click) but the light never extinguishes. I have
> checked power to the ABS control unit and it it there. Any thoughts on how
> to diagnosis and how much for a repl control unit???

Some dealers would doubtless charge you $800 for a new control unit,
and then nip underneath the car and re-fit whichever of the wheel
sensors is _really_ causing the problem.

On cars with accelerometers (small black unit in a protective steel
tray under the back seat) it's simply that the connector has fallen
off the accelerometer.  Or the accelerometer itself has failed, though
that's pretty rare.

In both of the above cases, cycling the switch _should_ extinguish the
light for around ten seconds while the controller does its check.  If
the accelerometer is dead or open-circuit, the ABS warning light will
come on before the car moves.  If a sensor is mis-seated, it comes on
as soon as the vehicle is moving.  If a wheel sensor goes open-circuit,
I would presume the light would come on without motion.  Otherwise,
check the fuse in the top of the ABS relay and swap the relay before
swapping the controller.

I've also heard of someone carrying a large and heavy drill in the boot
having it penetrate the boot lining and hit the ABS controller's
connector retaining clip.  Dead clip - connector falls out.  Got to be
one of the freakiest things ...

--
 Phil Payne
 Phone: 0385 302803   Fax: 01536 723021
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