ABS light on

The ABS light has just started to come on, on my 318 (1998) any ideas?

Fluke

Defective speed sensor on one of the wheels.




"fluke" <noaddress as > wrote in message
...
> The ABS light has just started to come on, on my 318 (1998) any ideas?
>
> Fluke
>
>

"fluke" <noaddress as > wrote in message
...
> The ABS light has just started to come on, on my 318 (1998) any ideas?
>
> Fluke
>
>

ABS sensor probably.. I wrote this for a forum I go to.. can help you do the
job yourself.. I've also done the rear ones too.. you'll need a drill to
drill out the old sensor..

***** POST *****
Firstly, I didn't think all this up myself I used some other posts on the
site... one from cotty in particular..

http://www.e36coupe.co.uk/forum/view...e+res istance

Which can be found there, but I thought I'd write up what I did when my ABS
light came on, because I haven't found a complete guide to the repair as of
yet on here..

First job is to test the sensors, from what I have read the front sensors
tend to go more frequently, so I'd start with those. They are also easier to
test. You'll need a voltmeter, very sensitive (milli-volts), you can
measure the resistance too, but I found that difficult (see cottys post).
Anyway.. remove the front wheel you're looking at, the sensor is located
within the wheel hub, but the connector in question is actually located
behind a black plastic casing, which is attached to the inside of the wheel
arch. One of the front wheels will also have a break pad sensor. Basically
trace the cabling from the hub to the plastic cover attached to the back of
the wheel arch and open it.. The ABS sensor connector should be grey. The
black connector is for the brake pad wear sensor, and we won't need to look
at that.

Disconnect the grey connector, the top comes off leaving one half connected
to the car electronics (wire leading into engine bay) and the other attached
to the sensor... from Cotty's post we're interested in pins 2 and 3 only.
Use a small bit of wire and hold them onto pins a and 2 and connect your
meter to these. This is fiddly, and be careful not to bend the pins! (I did
this on one sensor.. and fortunately for me it turned out to be the one that
was duff!) once connected set the voltmeter to milli-volts AC and rotate the
hub, the voltage should rise and lower with the hub speed. If is doesn't,
my advice is persist a while to see if you have made a mistake with the
settings on the meter, or the wires are not in contact with the pins, a
little time and effort is a good thing, you'll only have to repeat it later
if you're not sure you got the right readings which means more time wasted.
Repeat this step for both the front wheels, if you find a duff sensor, my
advice is continue to check the others, sometimes more than one fails.

The rear sensors are a little different, again one wheel will have the brake
pad sensor, I found mine to be the opposite side to the front. To do the
rear sensors, I found jacking the car at the back leaving the wheels on.. to
be sufficient (please be carefull when jacking the back don't want people
with cars dropped on their heads! good idea to use stands and blocks for the
front wheels to be secure). I didn't remove either of the rear wheels. The
sensor connectors once again are found in a black pastic like case that you
can open, one for each side, although for this they are tucked a little
further back. Best idea is trace the cables back from the sensors in the
hub to find them. Again same procedure, open the plastic covers, and take
out the grey connector, and separate it. There are only 2 pins in these
sensors, so it makes it easier, connect your voltmeter, same settings to
this and (making sure your handbrake is off) rotate the wheels. This is
where the jacking of the whole car comes in handy.. I found it hard rotating
the hub with the wheels off, with them on you can get more torque on the
wheel. Again the voltage reading should increase with the speed of the hub
rotation. And again, make sure that you have accurate readings and your
wires are secure.. will save time later.. don't want to do this again, it's
messy and unpleasant under the back!

By now hopefully one of these sensors will have shown NOT to change voltage
when the wheel spins. This is our target, buy a new sensor to replace it
from German Swedish French car parts, about 60 quid ish.. In my case it was
front right (51+vat), so I can talk you through the changing procedure for
the front sensors (which is a 5h1t to get out). Rear I am sure will be
similar.

Remove the wheel again, jack nice and securely, I also turn the wheels
left.. (for right side) so I can get a better view of the sensor. Remove
the allen key bolt that holds the sensor in place. You'll notice on the hub
there is a small cab which can be removed with an allen key. This is a cap
for the sensor, it lines up directly with it from the front and allows you
to insert a rod to use to push the sensor out this way. The sensors fit
using what I think is called and "interference fit" which means they are
VERY tight to get both in and out... Drilling out the sensor can loosen it
but I would try others ideas (I don't know who suggested it but it was not
me.. don't want to steal anyone elses thunder) soaking it in WD40 (do NOT
get it on your discs!) over night can be a good idea they get pretty stuck
in there. Be prepared for a long slog they are horrible to get out.
Inserting the sensor is not as hard but is not easy, again the purpose of
the interference fit is to jam the sensor in firmly.. which is really what
we want from this! once the new sensor is fitted, make sure you replace the
cap you removed from the hub, re connect the sensor, making sure the wires
are clipped where the previous wires were clipped. I gave my arches a good
clean up too while I was in there. Re-fit the wheel and drop the car back
down... Go to start, and in theory the ABS light should flicker and go off.
In my case the car did not even need to be started or moving....

I hope this helps anyone with ABS problems in future.. If anyone wants to
add anything to it or correct anything please do so...

Cheers all...

*** POST END****

Hope it helps...

"C.Read" > wrote in message
...
>
> "fluke" <noaddress as > wrote in message
> ...
> > The ABS light has just started to come on, on my 318 (1998) any ideas?
> >
> > Fluke
> >
> >
>
> ABS sensor probably.. I wrote this for a forum I go to.. can help you do
the
> job yourself.. I've also done the rear ones too.. you'll need a drill to
> drill out the old sensor..
>
> ***** POST *****
> Firstly, I didn't think all this up myself I used some other posts on the
> site... one from cotty in particular..
>
>
http://www.e36coupe.co.uk/forum/view...t=abs+resisten
ce+resistance
>
> Which can be found there, but I thought I'd write up what I did when my
ABS
> light came on, because I haven't found a complete guide to the repair as
of
> yet on here..
>
> First job is to test the sensors, from what I have read the front sensors
> tend to go more frequently, so I'd start with those. They are also easier
to
> test. You'll need a voltmeter, very sensitive (milli-volts), you can
> measure the resistance too, but I found that difficult (see cottys post).
> Anyway.. remove the front wheel you're looking at, the sensor is located
> within the wheel hub, but the connector in question is actually located
> behind a black plastic casing, which is attached to the inside of the
wheel
> arch. One of the front wheels will also have a break pad sensor.
Basically
> trace the cabling from the hub to the plastic cover attached to the back
of
> the wheel arch and open it.. The ABS sensor connector should be grey. The
> black connector is for the brake pad wear sensor, and we won't need to
look
> at that.
>
> Disconnect the grey connector, the top comes off leaving one half
connected
> to the car electronics (wire leading into engine bay) and the other
attached
> to the sensor... from Cotty's post we're interested in pins 2 and 3 only.

> Use a small bit of wire and hold them onto pins a and 2 and connect your
> meter to these. This is fiddly, and be careful not to bend the pins! (I
did
> this on one sensor.. and fortunately for me it turned out to be the one
that
> was duff!) once connected set the voltmeter to milli-volts AC and rotate
the
> hub, the voltage should rise and lower with the hub speed. If is doesn't,
> my advice is persist a while to see if you have made a mistake with the
> settings on the meter, or the wires are not in contact with the pins, a
> little time and effort is a good thing, you'll only have to repeat it
later
> if you're not sure you got the right readings which means more time
wasted.
> Repeat this step for both the front wheels, if you find a duff sensor, my
> advice is continue to check the others, sometimes more than one fails.
>
> The rear sensors are a little different, again one wheel will have the
brake
> pad sensor, I found mine to be the opposite side to the front. To do the
> rear sensors, I found jacking the car at the back leaving the wheels on..
to
> be sufficient (please be carefull when jacking the back don't want people
> with cars dropped on their heads! good idea to use stands and blocks for
the
> front wheels to be secure). I didn't remove either of the rear wheels.
The
> sensor connectors once again are found in a black pastic like case that
you
> can open, one for each side, although for this they are tucked a little
> further back. Best idea is trace the cables back from the sensors in the
> hub to find them. Again same procedure, open the plastic covers, and take
> out the grey connector, and separate it. There are only 2 pins in these
> sensors, so it makes it easier, connect your voltmeter, same settings to
> this and (making sure your handbrake is off) rotate the wheels. This is
> where the jacking of the whole car comes in handy.. I found it hard
rotating
> the hub with the wheels off, with them on you can get more torque on the
> wheel. Again the voltage reading should increase with the speed of the
hub
> rotation. And again, make sure that you have accurate readings and your
> wires are secure.. will save time later.. don't want to do this again,
it's
> messy and unpleasant under the back!
>
> By now hopefully one of these sensors will have shown NOT to change
voltage
> when the wheel spins. This is our target, buy a new sensor to replace it
> from German Swedish French car parts, about 60 quid ish.. In my case it
was
> front right (51+vat), so I can talk you through the changing procedure for
> the front sensors (which is a 5h1t to get out). Rear I am sure will be
> similar.
>
> Remove the wheel again, jack nice and securely, I also turn the wheels
> left.. (for right side) so I can get a better view of the sensor. Remove
> the allen key bolt that holds the sensor in place. You'll notice on the
hub
> there is a small cab which can be removed with an allen key. This is a
cap
> for the sensor, it lines up directly with it from the front and allows you
> to insert a rod to use to push the sensor out this way. The sensors fit
> using what I think is called and "interference fit" which means they are
> VERY tight to get both in and out... Drilling out the sensor can loosen it
> but I would try others ideas (I don't know who suggested it but it was not
> me.. don't want to steal anyone elses thunder) soaking it in WD40 (do NOT
> get it on your discs!) over night can be a good idea they get pretty stuck
> in there. Be prepared for a long slog they are horrible to get out.
> Inserting the sensor is not as hard but is not easy, again the purpose of
> the interference fit is to jam the sensor in firmly.. which is really what
> we want from this! once the new sensor is fitted, make sure you replace
the
> cap you removed from the hub, re connect the sensor, making sure the wires
> are clipped where the previous wires were clipped. I gave my arches a
good
> clean up too while I was in there. Re-fit the wheel and drop the car back
> down... Go to start, and in theory the ABS light should flicker and go
off.
> In my case the car did not even need to be started or moving....
>
> I hope this helps anyone with ABS problems in future.. If anyone wants to
> add anything to it or correct anything please do so...
>
> Cheers all...
>
> *** POST END****
>
> Hope it helps...
>
>

Thanks for this - will hope to add/return as I check these sensors soon.

Fluke

It is not normal that one would need a drill to get the sensors out. Let me
rephrase that, I took all of my sensors out with out the need for a drill.
The sensors are a very snug fit in the hole they go into, and a bit of
Liquid Wrench may help to get them free if they are stuck.

Another possibility is that there is trouble with the ABS relay body or
solenoid body, or whatever they call it. Look in the engine bay for the
thingie that has all of the brake pipes connected to it, this thingie has
solenoid operated valves inside. If one or more valves is sticky, the ABS
light will come on, which indicates the vehicle's ABS System is disabled.

When you start the car, the ABS light is among the lights that come on
during the self-test. It should go out when the engine is started and remain
out. If the light comes back on or remains on all of the time AND the
vehicle is not moving, then the speed sensors are most likely not part of
the trouble, and you need to service the solenoid body -- sometimes you can
flush the brake fluid and clear the debris that is clogging the valve(s). If
the ABS light goes out after engine start while the vehicle is not moving,
but then comes on after the car starts rolling, or comes on randomly as you
drive around, then the speed sensors move to the head of the line for things
to replace.

Before you do anything, you need to determine what mode the vehicle is in --
moving or stationary -- when the light comes on.

Jeff Strickland wrote:
>It is not normal that one would need a drill to get the sensors out. Let me
>rephrase that, I took all of my sensors out with out the need for a drill.
>The sensors are a very snug fit in the hole they go into, and a bit of
>Liquid Wrench may help to get them free if they are stuck.
>
>Another possibility is that there is trouble with the ABS relay body or
>solenoid body, or whatever they call it. Look in the engine bay for the
>thingie that has all of the brake pipes connected to it, this thingie has
>solenoid operated valves inside. If one or more valves is sticky, the ABS
>light will come on, which indicates the vehicle's ABS System is disabled.
>
>When you start the car, the ABS light is among the lights that come on
>during the self-test. It should go out when the engine is started and remain
>out. If the light comes back on or remains on all of the time AND the
>vehicle is not moving, then the speed sensors are most likely not part of
>the trouble, and you need to service the solenoid body -- sometimes you can
>flush the brake fluid and clear the debris that is clogging the valve(s). If
>the ABS light goes out after engine start while the vehicle is not moving,
>but then comes on after the car starts rolling, or comes on randomly as you
>drive around, then the speed sensors move to the head of the line for things
>to replace.
>
>Before you do anything, you need to determine what mode the vehicle is in --
>moving or stationary -- when the light comes on.
and if its not the sensors, and it ends up being the ABS/ASC module, there
are two ways to get it. you can get the whole unit which is over 1,000 bucks
i think, or you can just get the repair kit which is a new control unit
section of the module, without the hydraulic portion. there are torx screws
that hold it on, its easier, cheaper, and you wont have to do a bleeding
procedure either (which needs to be done with a BMW DIS tester hooked up)

"bbeyer" <u27223@uwe> wrote in message news:66f2313a151a1@uwe...
> Jeff Strickland wrote:
>>It is not normal that one would need a drill to get the sensors out. Let
>>me
>>rephrase that, I took all of my sensors out with out the need for a drill.
>>The sensors are a very snug fit in the hole they go into, and a bit of
>>Liquid Wrench may help to get them free if they are stuck.
>>
>>Another possibility is that there is trouble with the ABS relay body or
>>solenoid body, or whatever they call it. Look in the engine bay for the
>>thingie that has all of the brake pipes connected to it, this thingie has
>>solenoid operated valves inside. If one or more valves is sticky, the ABS
>>light will come on, which indicates the vehicle's ABS System is disabled.
>>
>>When you start the car, the ABS light is among the lights that come on
>>during the self-test. It should go out when the engine is started and
>>remain
>>out. If the light comes back on or remains on all of the time AND the
>>vehicle is not moving, then the speed sensors are most likely not part of
>>the trouble, and you need to service the solenoid body -- sometimes you
>>can
>>flush the brake fluid and clear the debris that is clogging the valve(s).
>>If
>>the ABS light goes out after engine start while the vehicle is not moving,
>>but then comes on after the car starts rolling, or comes on randomly as
>>you
>>drive around, then the speed sensors move to the head of the line for
>>things
>>to replace.
>>
>>Before you do anything, you need to determine what mode the vehicle is
>>in --
>>moving or stationary -- when the light comes on.


> and if its not the sensors, and it ends up being the ABS/ASC module, there
> are two ways to get it. you can get the whole unit which is over 1,000
> bucks
> i think, or you can just get the repair kit which is a new control unit
> section of the module, without the hydraulic portion. there are torx
> screws
> that hold it on, its easier, cheaper, and you wont have to do a bleeding
> procedure either (which needs to be done with a BMW DIS tester hooked up)
>


I'm not sure I made it clear, but the ABS system talks to the Diagnostic
Port, so one need only visit an independent BMW service center to plug into
the diagnostics and find out what the car thinks it is unhappy about.

"Jeff Strickland" > wrote in message
...
>
> "bbeyer" <u27223@uwe> wrote in message news:66f2313a151a1@uwe...
> > Jeff Strickland wrote:
> >>It is not normal that one would need a drill to get the sensors out. Let
> >>me
> >>rephrase that, I took all of my sensors out with out the need for a
drill.
> >>The sensors are a very snug fit in the hole they go into, and a bit of
> >>Liquid Wrench may help to get them free if they are stuck.
> >>
> >>Another possibility is that there is trouble with the ABS relay body or
> >>solenoid body, or whatever they call it. Look in the engine bay for the
> >>thingie that has all of the brake pipes connected to it, this thingie
has
> >>solenoid operated valves inside. If one or more valves is sticky, the
ABS
> >>light will come on, which indicates the vehicle's ABS System is
disabled.
> >>
> >>When you start the car, the ABS light is among the lights that come on
> >>during the self-test. It should go out when the engine is started and
> >>remain
> >>out. If the light comes back on or remains on all of the time AND the
> >>vehicle is not moving, then the speed sensors are most likely not part
of
> >>the trouble, and you need to service the solenoid body -- sometimes you
> >>can
> >>flush the brake fluid and clear the debris that is clogging the
valve(s).
> >>If
> >>the ABS light goes out after engine start while the vehicle is not
moving,
> >>but then comes on after the car starts rolling, or comes on randomly as
> >>you
> >>drive around, then the speed sensors move to the head of the line for
> >>things
> >>to replace.
> >>
> >>Before you do anything, you need to determine what mode the vehicle is
> >>in --
> >>moving or stationary -- when the light comes on.
>
>
> > and if its not the sensors, and it ends up being the ABS/ASC module,
there
> > are two ways to get it. you can get the whole unit which is over 1,000
> > bucks
> > i think, or you can just get the repair kit which is a new control unit
> > section of the module, without the hydraulic portion. there are torx
> > screws
> > that hold it on, its easier, cheaper, and you wont have to do a bleeding
> > procedure either (which needs to be done with a BMW DIS tester hooked
up)
> >
>
>
> I'm not sure I made it clear, but the ABS system talks to the Diagnostic
> Port, so one need only visit an independent BMW service center to plug
into
> the diagnostics and find out what the car thinks it is unhappy about.
>
>
>
>

I've had some good ideas from you and the other posters here, the cars my
gaffa's - he is going to sell but he wants the light out before hand.
Ive told him I'm doing no dodgy stuff, I also explained him to be certain he
would need to take it to a BMW service centre.
Thanks again
Fluke.

Just going through this myself..
here's my dramas so far..
car is new to us (though was born in 95) and sure enough the ABS lamp
came on within minutes of us owning it..

The light comes on as soon as the ignition is turned - I pray to the god
of ABS pumps and offer some skin off my knuckes and a set of multimeter
leads trying to measure just one of the 4 sensors (yep that one was OK)
It started raining heavily and the missus needed the car so I have to
abandon play

Decided to just get the brain read and have done with it...£20 lighter
but at least I know its the front drivers side sensor that's gone

order a new sensor (£70 lighter - but at least I will know what ABS
feels like and will extinguish the lamp on the dash!)

took wheel off, took sensor connector from its plastic housing and put
new leads across pins....bingo the brain reading seems to be telling the
truth - 0 ohms - open circuit

decided to get a new "L shaped" allen key (ever the optimist) and tapped
it into the sensor bolt head put some release fluid on there - tapped it
a few more times to try and get the fluid in there - went and had a cup
of tea and degreased my hands
went to the allen key, gingerly put pressure on, no loud snap - just a
soft chewy tear - more lost skin from knuckles, head still attached to
allen key - end of thread still in sensor/hub, DOH!

Ok get mole grips and gently twist sensor body, rocking it back and
forth whist using a pulling motion it eventually came out,without any
real dramas
compared it to new sensor - and its a different design,,,,,,

Old one has a chromed metal body and 2 pins in connector - and an earth
wire from chassis body to sensor body
New one is made from black plastic (ok so it won't seize if you don't
put coppaslip or whatever in there) - but it also has 3 pins in the
connector

Put wheel back on sulked for a while...

Tomorrow I'm giving car back to the garage where I bought the new sensor
and getting them to drill the remains of the bolt out and fit a
replacement sensor as I really couldn't face trying to get the brake
disk (rotor) allen bolt out to try and get to the back of the sensor
bolt to have a go at drilling it and chasing the thread myself - not
that I have the correct sensor to refit anyway...besides I have lost
enough skin for one week on this car
(I knew it wasn't going to be a 10 minute job - they never are)
I never expected it to be a three figure ammount to extinguish the bulb

On the bright side it means I get to drive my kit car (lotus 7 clone) to
work tomorrow for the last time on standard carbs
hoping to loose some more skin fitting a set of motorcycle carbs to it
on Thursday :-)
Had the bolts in and out so many times I know they won't cause any
dramas replacing them

pray for good weather tomorrow -as it has no windscreen or roof
I will be offering a sacrifice to the skin gods for Thursday's encounter
and be taking waterproofs to work

I think the moral of the story is getting someone else to do a job you
are really not geared up for - is really much cheaper,easier and quicker
in the long run

I wish I had the gear to read the brain, a decent set of allen key
sockets, a ramp, a garage blah blah - but I don't, so will have to do
more overtime


Regards
Rob


"You can't have everything....where would you keep it?"
Steven Wright

In article >,
rob > wrote:
> Tomorrow I'm giving car back to the garage where I bought the new sensor
> and getting them to drill the remains of the bolt out and fit a
> replacement sensor as I really couldn't face trying to get the brake
> disk (rotor) allen bolt

I've just changed all the discs on my '97, and they all came out easily.
As they did the last time - although I do use a smear of copper grease on
them

--
*Middle age is when it takes longer to rest than to get tired.

Dave Plowman London SW
To e-mail, change noise into sound.