[s-cars] Re ABS issue

[Tom Green]

The C4 sensors slide in a socket.  Later models started using a  
plastic holder that is fastened in place,  I'm not sure what you will  
find on yours, but the URS sensors
were more likely to just be out of adjustment from someone pulling on  
the cable when doing other work on the strut.

Since it is an intermittent fault, they go away quickly during normal  
driving if the ABS light is not on continuously.  You may have to  
trigger the fault in your driveway and check for DTCs, or even put the  
car on a lift and rotate the wheels then brake to trigger the fault  
while checking for codes.

Tom

On Jan 12, 2010, at 2:46 PM, Young, Steve wrote:

>
> Thanks Tom.  I sent that email last night while travelling in CT and  
> don't have my VAG-COM with me.  However, you hit the nail --> head  
> when you mentioned 3 to 4 pulses just before the stop.  That is  
> exactly the symptom.
>
>
> Regards,
>
> Steven Young, CEM
> Project Developer - Connecticut / New York / Vermont Territory
> ____________________________________TRANE
> 301 Old Niskayuna Rd., Latham, NY  12110
> Tel: 518.724.1453
> Fax: 518.785.4359
>
> www.trane.com
>
> P Please consider the environment before printing this e-mail
>
> -----Original Message-----
> From: Tom Green [mailto:trgreen at comcast.net]
> Sent: Tuesday, January 12, 2010 12:37 PM
> To: s-car-list at audifans.com
> Cc: Young, Steve
> Subject: Re[s-cars] ABS issue
>
> Steve,
>
> Before you get your hands dirty putting this thing on the rack and
> checking all those wheel sensors, why not read the codes?  If you have
> a malfunctioning wheel
> sensor it should be storing a code for that wheel sensor.
>
> If it is just out of adjustment or full of crud in the spokes, it will
> probably only activate just before you reach a complete stop;  i.e. ,
> only 3 or 4 quick pulses.
>
> Tom
>
>> -----Original Message-----
>> Date: Tue, 12 Jan 2010 05:31:35 -0800 (PST)
>> From: mike schowengerdt <urdrquattro at yahoo.com>
>> Subject: Re: [s-cars] ABS issue
>> To: "Young, Steve" <sryoung at trane.com>, S-Cars
>>      <s-car-list at audifans.com>
>> Message-ID: <962626.15758.qm at web83003.mail.mud.yahoo.com>
>> Content-Type: text/plain; charset=iso-8859-1
>>
>> first thing to do is re-seat all wheeel speed sensors , if that
>> doesn't do it , pull them out and look carefully at the speed rings
>> (rotate the axle and look all the way around for cracks or rust
>> filled teeth) most common problem is the front sensors get disturbed
>> when cv joint or suspension work is done.........HTH............m
>>
>> ________________________________
>> From: "Young, Steve" <sryoung at trane.com>
>>
>> Lister...
>>
>> Let me start by saying this could conceivably apply to any ABS
>> equipped car.? I bought a B5 A4 Avant, 2.8L, 5sp about 15 months
>> ago.? I bought it with the ABS light on and the flashing brake
>> light.? Typical ABS module failure.? I got around to having it
>> rebuilt last month.? Reinstalled it and no lights...cool.? Or so I
>> thought.? Now I have the ABS activating on 9 out of 10 stops
>> regardless of road condition.? I am not convinced it is the module,
>> and can't help but wonder if this situation is what caused the
>> module to fail in the first place.? Could this be a bad wheel speed
>> sensor fooling the ABS system into thinking it needs to compensate
>> for slippery road conditions at all times?? Anyone dealt with this
>> issue before??? TIA
>>
>
>
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