95/M Cavalier, 102,000 miles, 2.0i Ecotec lump.

I was dismayed when the ABS light failed to go out after starting a few
days ago, as I know ABS faults can be expensive.  Initially I put it
down to a wet sensor or connection after driving through a puddle (I'm a
big kid really :)

Over the next few days, the behaviour of the light became erratic.
Sometimes it would go out normally a couple of seconds after switch-on,
sometimes it would come on while driving.  Googling found this link:

http://www.cavweb-forums.co.uk/showthread.php?t=104

which says that a faulty brake light can cause the ABS warning lamp to
come on.  Checked and found that one bulb was indeed not working, though
the filament looks fine under a magnifying glass.

Replaced both brake bulbs and the light has not come on since (apart
from the normal bulb check at switch-on) and the ABS does work - I tried
braking hard on a clear road in the wet.

Any thoughts?  It doesn't seem right to me that a blown brake light bulb
can cause the ABS system to log a fault.  The user's manual is silent on
the subject as usual, telling me only to take the car to a main dealer
with a handful of cash at the ready.

"Mike Tomlinson"  wrote in message 
news:+ihcM3IQ4mvCFwuM@jasper.org.uk...

>
> 95/M Cavalier, 102,000 miles, 2.0i Ecotec lump.
>
> I was dismayed when the ABS light failed to go out after starting a few
> days ago, as I know ABS faults can be expensive.  Initially I put it
> down to a wet sensor or connection after driving through a puddle (I'm a
> big kid really :)
>
> Over the next few days, the behaviour of the light became erratic.
> Sometimes it would go out normally a couple of seconds after switch-on,
> sometimes it would come on while driving.  Googling found this link:
>
> http://www.cavweb-forums.co.uk/showthread.php?t=104
>
> which says that a faulty brake light can cause the ABS warning lamp to
> come on.  Checked and found that one bulb was indeed not working, though
> the filament looks fine under a magnifying glass.
>
> Replaced both brake bulbs and the light has not come on since (apart
> from the normal bulb check at switch-on) and the ABS does work - I tried
> braking hard on a clear road in the wet.
>
> Any thoughts?  It doesn't seem right to me that a blown brake light bulb
> can cause the ABS system to log a fault.  The user's manual is silent on
> the subject as usual, telling me only to take the car to a main dealer
> with a handful of cash at the ready.
>


certainly this is the case with Honda abs, so I see no reason Vauxhall 
should be different, also it stops the cruise control!

mrcheerful

"Mike Tomlinson"  wrote in message 
news:+ihcM3IQ4mvCFwuM@jasper.org.uk...

>
> 95/M Cavalier, 102,000 miles, 2.0i Ecotec lump.
>
> I was dismayed when the ABS light failed to go out after starting a few
> days ago, as I know ABS faults can be expensive.  Initially I put it
> down to a wet sensor or connection after driving through a puddle (I'm a
> big kid really :)
>
> Over the next few days, the behaviour of the light became erratic.
> Sometimes it would go out normally a couple of seconds after switch-on,
> sometimes it would come on while driving.  Googling found this link:
>
> http://www.cavweb-forums.co.uk/showthread.php?t=104
>
> which says that a faulty brake light can cause the ABS warning lamp to
> come on.  Checked and found that one bulb was indeed not working, though
> the filament looks fine under a magnifying glass.
>
> Replaced both brake bulbs and the light has not come on since (apart
> from the normal bulb check at switch-on) and the ABS does work - I tried
> braking hard on a clear road in the wet.
>
> Any thoughts?  It doesn't seem right to me that a blown brake light bulb
> can cause the ABS system to log a fault.  The user's manual is silent on
> the subject as usual, telling me only to take the car to a main dealer
> with a handful of cash at the ready.
>
>
>


Take the bulb out of the ABS light. That'll fix it boy.

Ted Rubberford.
The Man In The Latex Skirt.

"Ted Rubberford"  wrote in message 
news:1119776905.13237.0@ersa.uk.clara.net...

>
> "Mike Tomlinson"  wrote in message 
> news:+ihcM3IQ4mvCFwuM@jasper.org.uk...
>>
>> 95/M Cavalier, 102,000 miles, 2.0i Ecotec lump.
>>
>> I was dismayed when the ABS light failed to go out after starting a few
>> days ago, as I know ABS faults can be expensive.  Initially I put it
>> down to a wet sensor or connection after driving through a puddle (I'm a
>> big kid really :)
>>
>> Over the next few days, the behaviour of the light became erratic.
>> Sometimes it would go out normally a couple of seconds after switch-on,
>> sometimes it would come on while driving.  Googling found this link:
>>
>> http://www.cavweb-forums.co.uk/showthread.php?t=104
>>
>> which says that a faulty brake light can cause the ABS warning lamp to
>> come on.  Checked and found that one bulb was indeed not working, though
>> the filament looks fine under a magnifying glass.
>>
>> Replaced both brake bulbs and the light has not come on since (apart
>> from the normal bulb check at switch-on) and the ABS does work - I tried
>> braking hard on a clear road in the wet.
>>
>> Any thoughts?  It doesn't seem right to me that a blown brake light bulb
>> can cause the ABS system to log a fault.  The user's manual is silent on
>> the subject as usual, telling me only to take the car to a main dealer
>> with a handful of cash at the ready.
>>
>>
>>
>
> Take the bulb out of the ABS light. That'll fix it boy.
>
> Ted Rubberford.
> The Man In The Latex Skirt.
>


No.  That would disable the ABS, and mean it would fail the MoT, plus the 
brakes become dangerously unbalanced on some vehicles (granada springs to my 
mind very vividly)

mrcheerful

"Mike Tomlinson"  wrote in message
news:+ihcM3IQ4mvCFwuM@jasper.org.uk...

>
> 95/M Cavalier, 102,000 miles, 2.0i Ecotec lump.
>
> I was dismayed when the ABS light failed to go out after starting a few
> days ago, as I know ABS faults can be expensive.  Initially I put it
> down to a wet sensor or connection after driving through a puddle (I'm a
> big kid really :)
>
> Over the next few days, the behaviour of the light became erratic.
> Sometimes it would go out normally a couple of seconds after switch-on,
> sometimes it would come on while driving.  Googling found this link:
>
> http://www.cavweb-forums.co.uk/showthread.php?t=104
>
> which says that a faulty brake light can cause the ABS warning lamp to
> come on.  Checked and found that one bulb was indeed not working, though
> the filament looks fine under a magnifying glass.
>
> Replaced both brake bulbs and the light has not come on since (apart
> from the normal bulb check at switch-on) and the ABS does work - I tried
> braking hard on a clear road in the wet.
>
> Any thoughts?  It doesn't seem right to me that a blown brake light bulb
> can cause the ABS system to log a fault.  The user's manual is silent on
> the subject as usual, telling me only to take the car to a main dealer
> with a handful of cash at the ready.
>
>
> Put a defective brake light bulb back in and see if the abs light comes on

again then put the new bulb back in and see if the abs light stays out

Seems obvious but remove the possibility of coincidence at the time of the
original bulb change

Tony

>> Take the bulb out of the ABS light. That'll fix it boy.
>>
>> Ted Rubberford.
>> The Man In The Latex Skirt.
>>
>
> No.  That would disable the ABS, and mean it would fail the MoT, plus the 
> brakes become dangerously unbalanced on some vehicles (granada springs to 
> my mind very vividly)
>
> mrcheerful


Would it?  I'd have thought that if the ABS light's coming on it indicates a 
fault that's there, and removing it isn't neccessarily going to remove a 
vital link in the ABS circuit.  Sounds like it was just a blown brake light 
bulb anyway.

But surely if the ABS light wasn't visibly on for the MOT, then they 
wouldn't fail it, would they?  I mean, it's not like the brake rollers have 
got a mode to simulate traction becoming a bit of an issue, to actually 
properly test the ABS, is it?

Peter

In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
   AstraVanMan  wrote:

> But surely if the ABS light wasn't visibly on for the MOT, then they
> wouldn't fail it, would they?  I mean, it's not like the brake rollers
> have got a mode to simulate traction becoming a bit of an issue, to
> actually properly test the ABS, is it?


They check it works at switch on time. If it doesn't they just assume the
bulb has been removed because of a fault and fail the car anyway.

-- 
*A closed mouth gathers no feet.*

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

"AstraVanMan"  wrote in message
news:2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net...

> >> Take the bulb out of the ABS light. That'll fix it boy.
> >>
> >> Ted Rubberford.
> >> The Man In The Latex Skirt.
> >>
> >
> > No.  That would disable the ABS, and mean it would fail the MoT, plus
the
> > brakes become dangerously unbalanced on some vehicles (granada springs
to
> > my mind very vividly)
> >
> > mrcheerful
>
> Would it?  I'd have thought that if the ABS light's coming on it indicates
a
> fault that's there, and removing it isn't neccessarily going to remove a
> vital link in the ABS circuit.  Sounds like it was just a blown brake
light
> bulb anyway.
>
> But surely if the ABS light wasn't visibly on for the MOT, then they
> wouldn't fail it, would they?  I mean, it's not like the brake rollers
have
> got a mode to simulate traction becoming a bit of an issue, to actually
> properly test the ABS, is it?
>
> Peter


if its got ABS fitted and the ABS function light fails to display or doesn't
extinguish in the correct manner then its a fail. The correct sequence is
displayed on the ABS data chart that every MOT testing station must display.

"Dave Plowman (News)"  wrote in message 
news:4d81029df2dave@davenoise.co.uk...

> In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
>   AstraVanMan  wrote:
>> But surely if the ABS light wasn't visibly on for the MOT, then they
>> wouldn't fail it, would they?  I mean, it's not like the brake rollers
>> have got a mode to simulate traction becoming a bit of an issue, to
>> actually properly test the ABS, is it?
>
> They check it works at switch on time. If it doesn't they just assume the
> bulb has been removed because of a fault and fail the car anyway.


The bulb serves two purposes - in normal use it comes on when there's a 
problem, but at first switch on it acts as a self test - it comes on then 
once the system has checked itself out it goes out.

If it doesn't come on at startup the MOT treats it as a total ABS failure 
and fails it.

"Dave Plowman (News)"  wrote in message
news:4d81029df2dave@davenoise.co.uk...

> In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
>    AstraVanMan  wrote:
> > But surely if the ABS light wasn't visibly on for the MOT, then they
> > wouldn't fail it, would they?  I mean, it's not like the brake rollers
> > have got a mode to simulate traction becoming a bit of an issue, to
> > actually properly test the ABS, is it?
>
> They check it works at switch on time. If it doesn't they just assume the
> bulb has been removed because of a fault and fail the car anyway.


So all one needs to do is insulate the bulb from the PC board, and wire it
directly into the ignition switch with a delay timer.
Problem solved. :-)
Mike.

"Mike G"  wrote in message 
news:42bea627$0$2050$ed2e19e4@ptn-nntp-reader04.plus.net...

>
> "Dave Plowman (News)"  wrote in message
> news:4d81029df2dave@davenoise.co.uk...
>> In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
>>    AstraVanMan  wrote:
>> > But surely if the ABS light wasn't visibly on for the MOT, then they
>> > wouldn't fail it, would they?  I mean, it's not like the brake rollers
>> > have got a mode to simulate traction becoming a bit of an issue, to
>> > actually properly test the ABS, is it?
>>
>> They check it works at switch on time. If it doesn't they just assume the
>> bulb has been removed because of a fault and fail the car anyway.
>
> So all one needs to do is insulate the bulb from the PC board, and wire it
> directly into the ignition switch with a delay timer.
> Problem solved. :-)
> Mike.
>


but you won't know if the system works will you?  or at least not till after 
the crash you could have avoided, modifying the abs could even invalidate 
the insurance (if they find out)  So, all in all, not a good idea.

mrcheerful

>> So all one needs to do is insulate the bulb from the PC board, and wire 
>> it
>> directly into the ignition switch with a delay timer.
>> Problem solved. :-)
>
> but you won't know if the system works will you?  or at least not till 
> after the crash you could have avoided, modifying the abs could even 
> invalidate the insurance (if they find out)  So, all in all, not a good 
> idea.
>
> mrcheerful


I freely admit to knowing next to bugger all about ABS systems, but would a 
car with non-working ABS really be any more dangerous than the same car that 
just didn't have ABS to start with?

Peter

The message <ZsBve.4844$5D4.2023@newsfe4-win.ntli.net>
from "AstraVanMan"  contains
these words:


> I freely admit to knowing next to bugger all about ABS systems, but would a 
> car with non-working ABS really be any more dangerous than the same
> car that 
> just didn't have ABS to start with?


Potentially, yes. As I understand it, they lack a rear proportioning
valve, relying on the ABS to do the job of stopping the back brakes
locking. It it ain't working the back brakes will have nothing to keep
them in proportion to the fronts.

-- 
Skipweasel.
Ivor Cutler - "Never knowingly understood."

AstraVanMan wrote:

>>>So all one needs to do is insulate the bulb from the PC board, and wire 
>>>it
>>>directly into the ignition switch with a delay timer.
>>>Problem solved. :-)
>>
>>but you won't know if the system works will you?  or at least not till 
>>after the crash you could have avoided, modifying the abs could even 
>>invalidate the insurance (if they find out)  So, all in all, not a good 
>>idea.
>>
>>mrcheerful
> 
> 
> I freely admit to knowing next to bugger all about ABS systems, but would a 
> car with non-working ABS really be any more dangerous than the same car that 
> just didn't have ABS to start with?


Depends.

For instance, I believe some ABS systems do the front/rear load 
proportioning instead of a valve.  This is bad if the ABS system is not 
functioning and you decide to brake hard on a corner and the rears lock 
as they are given 50/50bias instead of whatever the computer thinks is 
appropriate.

I think Different systems fail in different ways.  If an ABS system 
thinks all the wheels are locked when they aren't it won't allow any 
braking force to be applied at all.  I think some systems have more 
reliable ways of ensuring this doesn't happen than others.

The ABS on my BX has pulled a couple of weird moves on me when I had a 
chafed sensor wire making intermittent contact.  After doing something 
funny and a fresh application of the brakes, it would usually decide 
something was amiss and switch the light on and stop ABSing.

Douglas

"Mike G"  wrote in message
news:42bea627$0$2050$ed2e19e4@ptn-nntp-reader04.plus.net...

>
> "Dave Plowman (News)"  wrote in message
> news:4d81029df2dave@davenoise.co.uk...
> > In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
> >    AstraVanMan  wrote:
> > > But surely if the ABS light wasn't visibly on for the MOT, then they
> > > wouldn't fail it, would they?  I mean, it's not like the brake rollers
> > > have got a mode to simulate traction becoming a bit of an issue, to
> > > actually properly test the ABS, is it?
> >
> > They check it works at switch on time. If it doesn't they just assume
the
> > bulb has been removed because of a fault and fail the car anyway.
>
> So all one needs to do is insulate the bulb from the PC board, and wire it
> directly into the ignition switch with a delay timer.
> Problem solved. :-)
> Mike.


not quite so simple Mike, re my earlier post all ABS systems follow a
function sequence.

from the testers manual.
1. if the vehicle is fitted with an anti-lock braking system, check that the
warning lamp.
a. illuminates
b. follows the correct sequence of operation. Note : the sequence varies
with the type of system. Refer to the manufacture's or other reliable data,
eg purpose produced charts, books ect.

reason for rejection.
a. the warning lamp does not illuminate.
b. the warning lamp does not follow the correct sequence of operation.
c. the warning lamp indicates an ABS fault.

this applies to all systems fitted as standard , and to ' optional ' systems
fitted.

In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>, 
Peter@Whataloadofforeskinbollocks.co.uk says...

> >> Take the bulb out of the ABS light. That'll fix it boy.
> >>
> >> Ted Rubberford.
> >> The Man In The Latex Skirt.
> >>
> >
> > No.  That would disable the ABS, and mean it would fail the MoT, plus the 
> > brakes become dangerously unbalanced on some vehicles (granada springs to 
> > my mind very vividly)
> >
> > mrcheerful
> 
> Would it?  I'd have thought that if the ABS light's coming on it indicates a 
> fault that's there, and removing it isn't neccessarily going to remove a 
> vital link in the ABS circuit.  Sounds like it was just a blown brake light 
> bulb anyway.
> 
> But surely if the ABS light wasn't visibly on for the MOT, then they 
> wouldn't fail it, would they?  I mean, it's not like the brake rollers have 
> got a mode to simulate traction becoming a bit of an issue, to actually 
> properly test the ABS, is it?


This is a funny one.

The light is only tested to show the ABS fail detect system is working. 
They don't care about ABS! Just the light.

I had a friend with a fault on their system which meant the light didn't go 
out *but* the ABS still worked fine.

This was an MOT fail.

If the light didn't go out *and* the ABS didn't work, the lights function 
is just right, so the garage said they would have passed it.

If the light didn't go out but the ABS does work, the light is 
malfunctioning, so it's a fail.

Pete.

-- 
NOTE! Email address is spamtrapped. Any email will be deleted
Remove the news and underscore from my address to reply by mail

"Pete Smith"  wrote in message
news:MPG.1d290295779e9b1198973a@usenet.plus.net...

> In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
> Peter@Whataloadofforeskinbollocks.co.uk says...
> > >> Take the bulb out of the ABS light. That'll fix it boy.
> > >>
> > >> Ted Rubberford.
> > >> The Man In The Latex Skirt.
> > >>
> > >
> > > No.  That would disable the ABS, and mean it would fail the MoT, plus
the
> > > brakes become dangerously unbalanced on some vehicles (granada springs
to
> > > my mind very vividly)
> > >
> > > mrcheerful
> >
> > Would it?  I'd have thought that if the ABS light's coming on it
indicates a
> > fault that's there, and removing it isn't neccessarily going to remove a
> > vital link in the ABS circuit.  Sounds like it was just a blown brake
light
> > bulb anyway.
> >
> > But surely if the ABS light wasn't visibly on for the MOT, then they
> > wouldn't fail it, would they?  I mean, it's not like the brake rollers
have
> > got a mode to simulate traction becoming a bit of an issue, to actually
> > properly test the ABS, is it?
>
> This is a funny one.
>
> The light is only tested to show the ABS fail detect system is working.
> They don't care about ABS! Just the light.
>
> I had a friend with a fault on their system which meant the light didn't
go
> out *but* the ABS still worked fine.
>
> This was an MOT fail.
>
> If the light didn't go out *and* the ABS didn't work, the lights function
> is just right, so the garage said they would have passed it.
>
> If the light didn't go out but the ABS does work, the light is
> malfunctioning, so it's a fail.
>
> Pete.
>


its not easy being an MOT tester, honest. some days you come up against
things or customers were you just wanna bang yer head against the wall .

two phrases are banged into us during mot refreshers.

C.Y.A = Cover Your Arse & P.A.N.D.A = Pass And Advise.

I must go through more advise pads then VT30 failure sheets !

"reg"  wrote in message
news:d9mr3p$lno$1@newsg4.svr.pol.co.uk...

>
> "Mike G"  wrote in message
> news:42bea627$0$2050$ed2e19e4@ptn-nntp-reader04.plus.net...
> >
> > "Dave Plowman (News)"  wrote in message
> > news:4d81029df2dave@davenoise.co.uk...
> > > In article <2Tuve.6836$zM2.6712@newsfe4-gui.ntli.net>,
> > >    AstraVanMan  wrote:
> > > > But surely if the ABS light wasn't visibly on for the MOT, then they
> > > > wouldn't fail it, would they?  I mean, it's not like the brake
rollers
> > > > have got a mode to simulate traction becoming a bit of an issue, to
> > > > actually properly test the ABS, is it?
> > >
> > > They check it works at switch on time. If it doesn't they just assume
> the
> > > bulb has been removed because of a fault and fail the car anyway.
> >
> > So all one needs to do is insulate the bulb from the PC board, and wire
it
> > directly into the ignition switch with a delay timer.
> > Problem solved. :-)
> > Mike.
>
> not quite so simple Mike, re my earlier post all ABS systems follow a
> function sequence.


I haven't noticed any variation in the check sequence with the ABS on
different cars.
They all seem to light the ABS warning bulb briefly when the ignition is
turned on, then go out.
I'm sure with a delay timer that sequence could be simulated well enough to
fool most MOT testers.
In any case, was only joking. It would probably be more hassle than fixing
the ABS properly.
Mike.

"AstraVanMan"  wrote in message

> I freely admit to knowing next to bugger all about ABS systems, but
> would a car with non-working ABS really be any more dangerous than the
> same car that just didn't have ABS to start with?


On a similar car I would say the working ABS one would be better. But
having recently drove my nephews 1987 VW Polo (non servo) which had just
passed it's MOT, I would say a non working ABS car with pads worn down
to the metal would still have better performing brakes than the Polo.

"Mark"  wrote in message
news:3i9ufoFkgrbtU1@individual.net...

> On a similar car I would say the working ABS one would be better. But
> having recently drove my nephews 1987 VW Polo (non servo) which had just
> passed it's MOT, I would say a non working ABS car with pads worn down
> to the metal would still have better performing brakes than the Polo.


Wasn't the middle pedal purely ornamental on Polos and floGs of that
vintage?

Carl Bowman (carlbowmanwithoutspam@gmx.co.uk) gurgled happily, sounding 
much like they were saying :


> Wasn't the middle pedal purely ornamental on Polos and floGs of that
> vintage?


That'll be your famed VW quality and engineering, that will.

On Tue, 28 Jun 2005 13:55:40 +0100, Adrian  wrote:


> Carl Bowman (carlbowmanwithoutspam@gmx.co.uk) gurgled happily, sounding
> much like they were saying :
>
>> Wasn't the middle pedal purely ornamental on Polos and floGs of that
>> vintage?
>
> That'll be your famed VW quality and engineering, that will.




EEh wahat a pair of wusses, you can lock the wheels on a polo if you push  
hard enough.

Duncanwood (nipnews@dmx512.co.uk) gurgled happily, sounding much like
they were saying : 


>>> Wasn't the middle pedal purely ornamental on Polos and floGs of that
>>> vintage?

>> That'll be your famed VW quality and engineering, that will.

> EEh wahat a pair of wusses, you can lock the wheels on a polo if you
> push  hard enough.


<rolls eyes>

So they don't start, either?