ABS Fault!

[Quattro john]

Hi,
I have a 99 a4 quattro and the abs light comes on when you get to 75mph and hold it there for 2 mins,no other time does this happen. Checked with vag com and it said front right hand sensor.I then replaced the sensor ,cleared the fault code but still the light comes on under the same condition and vag com says the same thing front right hand sensor.Any ideas?
All the best John.

 

[Emmo]

sounds like you have a dodgy sensor,you will need to replace the abs sensor , i had an abs light on the dash and vagcom told me it was the front right sensor, I replaced it and the fault went away.
I got the sensor for about £13 and its easy to replace, take off the wheel and its located just behind the brake disc, unplug the connector, the sensor is just held on by one allen bolt, replace with the new sensor, plug it back in and wheel back on, clear the fault and your good to go.

 

[WHITEY_1]

£13 for a abs sensor i paid £69 for my old audi a4 and that was on a N 1996 Where did you get it so cheap?

 

[Quattro john]

Thanks for the reply. I have replaced the sensor ,cleared the code and then tried again. The fault still comes up as front right sensor. I bought the sensor from Audi and they checked it and said there was nothing wrong with the new sensor. Are you sure that the sensor is held in with an allen bolt?
Cheers John.

 

[Caesium]

maybe its the connection, look all along the wiring carefully to make sure there is no breaks. Was there any crud in the hole where the sensor fits?

 

[Quattro john]

I cleaned out the hole before fitting the new sensor. Surely if the wiring was faulty the fault would be there all the time. This only happens when you sit at 75mph for more than 2 mins.You can accelerate up beyond 75 and come back down ,and no problem. However sit a 75mph for 2 mins and the abs light comes on.Check with vag com and always front right sensor. Any ideas?
Cheers John.

 

[Caesium]

if you have replaced the sensor and its working ok then it sounds like the abs controller.
Maybe try swapping the 2 front sensors around, long shot but may indicate something.

 

[Quattro john]

Thanks for the help Chris , i'll give it a go.
Cheers John.

 

[Emmo]

£13 for a abs sensor i paid £69 for my old audi a4 and that was on a N 1996 Where did you get it so cheap?

I got it off ebay..


as for swapping the two sensors around, I dont think you can as the left hand side is made for the left and wont fit on the right and vice versa.

have you made sure the ring where the abs sensor senses from is not bent or dirty?

 

[Quattro john]

Thanks for that. I've tried another sensor but still comes on after a while. I will try and clean the ring on the cv joint and see if that helps. Any idea what the gap between the sensor and the ring is ?
Cheers John.

 

[terrysingh]

double check that the abs slots on the cv joint are clean, a missing reading caused by brake flakes or dust in the slots could cause this fault???

 

[Quattro john]

No problem i will clean the abs ring and see if that does it.

Many thanks John.

 

[Quattro john]

Finally got around to working on the car.....i removed the abs sensor and found the hole was all rusty and there should be a tapered tin holder (for want of a better word) that holds the sensor in the hole with a good tight fit.This part was corroded away to next to nothing. I remembered thankfully that i asked to keep the old sensor that "AUDI" had removed and in the box was the new holder. I fitted the holder and replaced the sensor. I then cleared the faults with vagcom and gave it a try. No abs fault now,its just a pitty that audi don't fit all the parts that you pay for as that would have been the problem gone for good and saved me the time and messing about.So i guess the moral of the story is just because they charge the earth doesn't mean there any good!
Many thanks to all the people who have given me help and advice to get to the bottom of this annoying problem.
Cheers John.

 

[Tommy uk]

Hi all, im new here, i got problem with abs and tc warning on dash, im driving audi a4 b6 convertible . When i started the car in the morning all is ok and no warning in dash , but when i start driving few mils , they coming up , i have scanned the car with vcds lite and it shows me
00290 - rear wheel speed sensor (g46)
30-00 open or short to plus

So i replace rear speed sensor , also rear wheel barring hub, brake light switch, after ive tried to clear the faults but cannot , it just pop in right away and the problem still shows , any ideas what it might be a issue ? Appreciated any help

 

[Tommy uk]

Already sorted myself...

 

[mickyh7]

Tommy, why dont you share your fix on here.
It would be helpful to other people who come on here looking for help !
Like you did !!!
Just saying like

 

[Tommy uk]

Hi , in my case was abs ecu fault, after changing wheel barring hub, sensor , brake switch light , i had to order 2nd hand unit matching to my existing one and replace it , connect vcds and recode to my car , whole job takes about 2 hours without remalting the brake system . Once coding is done and steering angle sensor calibrated , test drive need to be done by pressing brake pedal for few seconds then start driving for about a minute with 15-20mph and turning steering wheel once left about 90° and then in right 90° .all errors and dash warning lights will disappear by themselfs .

Thats all what it need to be done .

 

[mickyh7]

Cheers mate.
Thats going to be helpful.
Many thanks