Hi all,

New to this forum but just wondering if you guys can share a little tech advise.

I took my A3 to have the cause of the ABS warning light staying on identified. After a quick plug in, NSF wheel speed sensor was at fault. Great! I've just changed it but the light is still on!!!

I've checked the resistance of the new sensor and it's 1k Ohms, like the OSF. There's also a 2.5V feed to the cable as there is on the OSF.

For this reason, I'm wondering if the warning light needs to be reset, using the diagnostic kit again??

I don't want to assume, as the light has occasionally gone off all by itself during the time the fault was present, before diagnostics.

Cheers for any help.

 

Hi,

I am not sure how to change the lights but I also have the same problem. I think that my ABS wheel snesor is broken and I was wondering if you could provide me with some tips on how I can replace it.

 

Hi lowtina,
Yes I believe you will need to get the faults deleted in order for the light to go off.



AudimaniaA4: The best thing would be to check its the sensor first and also find out which one is faulty, pop into a garage and see if they are able to just plug it into the VAGCOM machine. As for changing it I have been told the best bet is to drill the old one out and just use a new bolt as they seize in place (You will need to remove the calliper and disc first).

,Dave

 

Thanks for the input,

Interestingly, I have now switched the ABS warning light off!

Long story, but basically, having changed the sensor, the car was carefully driven round the block in an attempt to switch off the light. It didn't. The car has been immobile since, due to a sheared bleed nipple. That was sorted last night and so I test drove the car again. I noticed that on my gravel drive, the ABS did operate so I guessed that it did work, it just needed the fault reset.

However, the light has switched itself off before. So I went for a harder run. And, low and behold, when fully testing the ABS at 40mph, the light then went off and the ABS works beautifully!!! Happy man!! I guess the system just needs to fully recognise the new sensor.

Right then, as far as removing sensors is concerned, the Audi is one of the worst I've ever done!! Not that it's hard to get at. Just annoyingly stubborn!

The front sensors are located on the rear of the bearing carrier, near the caliper. There is a fixing bolt but this is just a token gesture as the sensor is held in better than the caliper by rust, dirt, age, etc, etc.

Unless you're really lucky, the sensor will have to be destroyed to get it out. So check it with a multimeter first. It's resistance should be 1050 Ohms ish. If it's no good, you'll probably see an open circuit.

Now comes the fun part!! Ubolt the caliper slide bolts and move the caliper to one side. Remove the disc too. Unplug the sensor, then snap off the rear part of the sensor by trying to lever the sensor from the bearing carrier. It will snap off!! Next, break away the nose of the sensor and bend down the metal tabs. Be careful not to damage the sensor ring in front of it. Now, using a suitable socket, tap the remaining part of the sensor through the hole.

With the sensor removed, use a file or wet and dry to clean up the hole the sensor passes through or you'll struggle getting the new one in. Be very careful fitting the new sensor. They're obsurdly delicate so it's hands only. No tapping!!!

I haven't looked at the rears yet but I'm assuming a similar story. This is definately possible for the DIY mechanic so don't let me put you off. Just be sure you've got suitable tools.

Thanks all.