blakep82
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| posted on 15/5/13 at 02:43 PM |
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1999 audi a4 ABS fault
you lot know everything, i've been searching over and over the internet, audi, vw forums, the lot, and i've not really found anything
conclusive.
got this on vagcom/vcds
00285 - ABS wheel speed sensor; Front right (G45)
30-00 open or short to plus
now, i've not registered the VCDS yet, will do when i get paid next week, but the next one is
00287 - ABS wheel speed sensor; Rear right (G44) (guessing from the fault codes on ross tech site)
35-00 (not sure what this bit would say. will register next week when i get paid)
i've taken a the front right wheel off, and put a mutimeter in the sensor plug, put the car in gear and let the clutch out, and can see that a
reading is being created by the wheel speed sensor, so the fault lies somewhere else.
anyone know?  i'm suspecting the abs module, i've seen some connections tend to break in there, but with very little experience in
soldering or electronics, i suspect i could make it a lot worse. the info on connections breaking in the abs module tend to have other faults showing
too, like missing comms and stuff, but i don't have these
any one sorted anything like this before? the aim is a free fix, as always with this car. so far all the major engine faults have been fixed for about
£30. ABS is the only major one left.
[Edited on 15/5/13 by blakep82]
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britishtrident
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| posted on 15/5/13 at 03:33 PM |
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Wiring faults are very common obviously the plug in the wheel arch but also water ingress corrosion the multiway plug at the ABS unit quite often
gives problems when this is the fault it is not unknown to have replace the both ABS unit AND part of the loom.
I would start by undoing the multiway connector at the ABS unit and checking the sensor from that there, you should also look for signs of
blue-green corrosion and the plug ans socket. If this is the case a clean with "Corrosion Gone" (available off ebay) or similar might
work but the pins on the ABS unit are very fragile and difficult to clean.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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blakep82
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| posted on 15/5/13 at 03:55 PM |
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The plug at the wheel end is up inside the wing behind a rubber grommet, so is nice and clean and dry. The multiplug is also clean and dry with no
corrosion.
Although, taking it off gave me an idea. If I knew what pins each sensor were on, I could stick the meter in the plug, spin the wheel again, and check
the signal reaches the plug. If it does, the fault must be in the module. The fix or replace
Its a bosch 5.3 I think?
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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Agriv8
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| posted on 15/5/13 at 04:24 PM |
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blake to test can you swap the abs sesors over from side to side and see of the fault stays or moves ?
hope that helps ( probably not )
Agriv8
PS let me know how you get on registering VCDS as thats my next 'treat to myself '
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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JAMSTER
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| posted on 15/5/13 at 04:40 PM |
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have a look here
http://www.bba-reman.com/content.aspx?content=audi_a4_amp_a6_1996_2001_and_vw_passat_1996_2001_abs_pumps_commonly_failing
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luke2152
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| posted on 15/5/13 at 06:41 PM |
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I have an a6 I have full version vcds and you can check individual wheel speeds as you drive (or preferably someone else driving....) but I'm in
Germany so can't help but maybe someone will be able to. When I had issues it was the abs ecu - cost me £80 for a used one. Be aware that
dealers will often tell you the abs pump has be replaced with the ecu but they are available separately
[Edited on 15/5/13 by luke2152]
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Bare
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| posted on 15/5/13 at 06:44 PM |
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Take care, Reman units often :-) are no better than the originals.
Sadly Bosch bits are Not the world's best quality imo.
Sometimes one can get "slightly' warranteed Parts from a Wreckers for surprisingly few $$
Check there first?
[Edited on 15/5/13 by Bare]
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mark chandler
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| posted on 15/5/13 at 06:53 PM |
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My ranger rover started throwing ABS faults, it was a shot wheel bearing in the end with the sensor at the limit of its working range.
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blakep82
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| posted on 15/5/13 at 08:03 PM |
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well, here's what i've been up to today:
front wheels off the ground
-as luke suggests, i plugged in VCDS, front and rear left show a speed, front and rear right, show zero.
-used a multimeter set to AC volts on the front right sensor, spun the wheel, shows 0.9 at idle speed, in gear.
with the sensor unplugged, checked continuity between the wheel speed sensor plug and the abs module plug. all ok there
-plugged it all back together and checked wheel speeds on VCDS, nothing for front right, but front left working fine
all seems to suggest the abs module.
HOWEVER
jumped the cables between the front left and front right sensors (ie feeding the left sensor signal into the right front cables) jammed the right
wheel so the left spins, plugged in VCDS and it shows 15km/h at both front wheels.
so, seems to suggest the ABS module is working, as it CAN get a signal from both sides
suggests the sensor is at fault; but i can get a reading from the multimeter off the front right sensor on its own
as far as i can tell, no individual part is at fault, but as a system as a whole, it doesn't work. total mystery to me
and i've not even started on the back one yet...
i guess a new sensor is the best place to start?
i changed the cv joint last week, but the fault was there before i changed it too.
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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PSpirine
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| posted on 15/5/13 at 08:20 PM |
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If you can get into the ABS module in vagcom, go to Measuring Blocks, either group 1 or 2 will be Wheel Speed.
Just hook it up and go for a drive and see whether the signal is intermittent or never there (for health and safety issues you should do this as a
passenger in the vehicle )
1) Wheel sensors are known to fail. £50 from VAG, £10-15 from ebay/GSF. Non-genuine quality varies.
2) Wheel sensors are so seized in on these cars that I'd be amazed if you managed to "swap two over" without actually breaking both
of them in the process.
3) Reluctor rings are known to rust and fail - fairly cheap and easy to replace.
I'd tackle the sensor/ring first, before even thinking about ABS ecu's or modulators (always fix by replacement starting from the cheapest
component!)
*ETA: not sure why it took so long to post, you've clearly done the wheel speed check, just saw your thread as it came up after I posted..
[Edited on 15/5/13 by PSpirine]
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luke2152
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| posted on 15/5/13 at 08:30 PM |
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That is not what mine was doing when the ecu was shot so hopefully nothing serious (mine wouldn't connect to the ecu module)
Did you take voltage off the good sensor to compare with the bad one?
Have you actually tested the abs with some heavy braking?
Could it be an intermittent fault with a dodgy wire or plug or is it failing all the time?
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britishtrident
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| posted on 15/5/13 at 08:32 PM |
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quote:
Originally posted by mark chandler
My ranger rover started throwing ABS faults, it was a shot wheel bearing in the end with the sensor at the limit of its working range.
Been there unless you have the right equipment tracking down faults on ABS systems with Hall Effect sensors is a pain in a+*^.
Thankfully I think the Audi has the old variable reluctance style sensors.
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
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blakep82
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| posted on 15/5/13 at 08:47 PM |
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quote:
Originally posted by luke2152
That is not what mine was doing when the ecu was shot so hopefully nothing serious (mine wouldn't connect to the ecu module)
Did you take voltage off the good sensor to compare with the bad one?
Have you actually tested the abs with some heavy braking?
Could it be an intermittent fault with a dodgy wire or plug or is it failing all the time?
when tested with the multimeter, both gave 0.8-0.9 as a reading. exaclty what the scale was, i don't know, but the reading were consistant
heavy braking you can feel the pedal pulsing, but you can get the wheels to lock.
before, the fault would only flash up on the dash around 60mph or so, come up once, and that was it. after i put the car back together, i went out for
milk, flashed up 3 times on the way there at all sorts of speed, and 4 times on the way home.
confused to say the least
i'll start with getting a new sensor, see how that works out i think? sound fair? even though i AM getting some sort of signal off it
so far i've fixed a non working turbo, low power, limp home mode, loads of black smoke, flat spots in acceleration, and a clicking CV joint for
the mega sum of about £25. this ABS is the last major fault to fix
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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wylliezx9r
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| posted on 15/5/13 at 09:22 PM |
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I've had a similar fault on a later model a3 and it was the sensor. As already said you need to be able to read the wheel speed live. Turned out
the faulty one on my car was reading double the speed of all the other sensors, just putting a meter across the sensor doesnt really tell you much.
The sensors on Audis are hall effect BTW.
Hth Dan
I spent a lot of money on booze, birds and fast cars. The rest I just squandered.
George Best
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blakep82
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| posted on 17/5/13 at 07:10 PM |
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well, could have sworn it would be a wiring fault, with it being the front and back right hand side at fault, and that the meter was showing it
worked, while VCDS showed nothing, new sensor came today, fitted, and it seems to work well now. still need to set it up right, as it reads 14kph
(thats what VCDS shows) where the left side shows 15, but i suspect it could do with being pushed in a tiny bit further. don't want to go too
far though. no way of knowing til it too late really...
back one's on order now.
Thanks for all the suggestions and help 
________________________
IVA manual link http://www.businesslink.gov.uk/bdotg/action/detail?type=RESOURCES&itemId=1081997083
don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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