ABS fault - now i'm desperate!

[imported_mc119856]

Ok so a while back i had an intermittent ABS warning light come up which in time became permenant. Diagnostics could not communicate with the ABS module so my 1st step was to replace it with a salvage part. After doing so the main brake warning & alarm went away but the yellow ABS light remained , and diagnostics could now read the module and give an error code '00287' which is the rear/right ABS sensor. I then replaced the sensor but the fault code remained.

I'm running out of ideas & money, do i assume that the salvaged ABS module came with a fault? or is there a problem elsewhere?

Please, can anyone help or suggest what to do next.

 

[mas]

check the wires ? connectors under the rear seats. Id be tempted to switch them (only for test purposes) and see if the fault moves to the rear left - if so its something on the rear right, if not its controller / cable to the rear seat.

have you inspected the reluctor ring ? I presume on an S4 it is like the quattro and its part of the cv joint, not on the disk like non-quattros.

 

[imported_mc119856]

Good thinking, i'll have a go at swapping the cables over.

 

[imported_mc119856]

I spoke with my main dealer & he seems to think that
the new ABS module needs to be 'coded' to the car, but everywhere i have read about changing these modules there was no mention of this, just a straight swap & possibly clearing down any previous error codes. Can anyone clarify this?

 

[RichA3Turbo]

Did you clear the codes with VAG-COM? If you dont clear codes, they wont go away by themselves...They have to be cleared.

Rich

 

[a4avant]

Check you have'nt fitted the new sensor the close to the "ring". Try pulling it back out very slightly. Does the ABS light clear on the dash then come back on again once the car is moving above 10mph?

 

[imported_mc119856]

[ QUOTE ]
Did you clear the codes with VAG-COM? If you dont clear codes, they wont go away by themselves...They have to be cleared.


[/ QUOTE ]

The slavaged ABS module was fitted at a local garage, they said that they cleared the
rear/right ABS sersor fault code using their own diag computer (not sure if its vag-com), but the fault would still return when the car was in motion. A week later the same garage replaced the sensor, cleared the fault but again it returned. I did see the sensor that was removed & it was worn down to an exposed coil
so it may be possible that it sits too far in.

 

[andyollie]

sounds like a bad sensor, take all out and clean htem, thats what i did, just disoccected battery for an hour to clear the code......

 

[a4avant]

The ABS is self testing everytime the ignition is switched on , it does'nt need reset by vag-com.

 

[imported_mc119856]

[ QUOTE ]
The ABS is self testing everytime the ignition is switched on , it does'nt need reset by vag-com.

[/ QUOTE ]

Well now when i turn the ignition the yellow ABS light is on (without the car moving). So if it is self testing would that point more to a problem on the ABS module rather then the sensor?

 

[mas]

Cant remember the exact details but theree is something on vag com about coding. I would have a look at the ross tech site for details. bba-reman have info on their site as well iirc.

My brother has my vagcom at the moment so I cant check.

I wouls seriously consider getting vag-com - or finding someone local with it - saves lots of time / money.

 

[imported_mc119856]

Just checked bba-reman tech forum & there is some mention of coding replacement units but does'nt go into much detail, ross-tech does mention coding but only when bleeding the abs pump. I dont think this applies as i only replaced the module & not the pump.

 

[RichA3Turbo]

[ QUOTE ]
The ABS is self testing everytime the ignition is switched on , it does'nt need reset by vag-com.

[/ QUOTE ]

You say that, but its not the case on the A3... I started car without ABS ECU plugged in when fitting my traction control system, and it logged a fault. Plugged it back in, and the fault didnt clear until i cleared it manually with vag-com

Rich

 

[docurley]

I had a faulty ABS unit on my 2.8 and replaced the whole ABS unit.

Bentley ABS info

Most of the info is in the link above.

Anyway I fitted the ABS unit myself and bleed the system and have never had a problem since I fitted it. I did not reset anything for the light to go out.

If you are unable to link to the ABS module then the fault is there and not anywhere else as you should be able to link with the module.