When I'm driving and slowing down at about 10mph there is a humming noise coming from under the hood on the drivers side and the brake pebal is vibranting till I come to a complete stop then it stops(the noise and the vibranting). And then when I take off the noise and vibranting starts again and stop after 10mph.

It feels like the brakes are taking to assist me when coming to a stop. This is under normal braking and driving. No fault codes stored. The brakes are working fine, the wheels are not locking up.

Is there a pre-charge pump on Audi's? Cause this is what it feels like.

 

I am currently having the same issue. I have had the ABS and Brake light on since I installed my new front suspension. This issue tends to come and go but as recently as today has started giving me the same exact problems you are having. Let me ask you this, when it acts up under braking for a stop, does it continue when you accelerate from a stop and prevent you from going above 10 MPH?

I'm 99% sure my ABS module is shot, and I have been wanting to see if removing it for repair will eliminate this problem.

If you have VAG-COM see if the program can communicate with the module.....if it can't, I believe it is shot. I found this to be the case at the Audi Dealer, they were not able to communicate with the module and told me it would be $1500 to fix. There are a few places online where one can send a defective ABS module for repair for 1/4 the price.

 

Yes it does continue when I accelerate but does not prevent me from going above 10mph. The noise and vibranting in the brake pebal go away after 10mph.

I know it is not the control module side of the ABS unit, because I just replace it. So I hope not. I think it is the ESP unit under the ABS unit, but not sure.

Question, what front suspension part did you install?

O and if you just unplug the connector on the ABS unit this issue will stop but your ABS warning lights will be on(but you said your lights were on). Braking will be normal but you can lock up your brakes under hard braking because you will not have ABS/ARS/ESP/EDL.

 

I had to replace all eight control arms. While I was at it, I installed sport springs and shocks as well. After the job was done I noticed I had the ABS and Brake light on all the time, but I was convinced it was due to removing the ABS Wheel Speed Sensors.

As I stated earlier, I had Audi diagnose the issue and they told me that they could not connect to the module which told them that the module was toast.

Thanks for the advice on unplugging the unit. I never even thought of that. Can I access the plug from above, or does it connect underneath?

 

Same problem, Vag-Com reports no issues, however my guess is a bad wheelspeed sensor which gets inaccurate around the 10-15 mph range (Exact same speed as mine does this) and engages abs due to it believing one of the wheels are sliding/locking.

 

How have you resolved your issue? Or is it ongoing?

May be the same issue with me, but I will try unplugging the ABS unit to prevent this from occurring in the first place. When I got to work the smell of brakes was nauseating.

It is entirely possible I may have damaged a wheel speed sensor upon removal/installation.........I'm still convinced its the module though.

 

ModuleMasters is your answer Drunk. My ABS wasn't communicating when I bought the car. Shipped the module to Idaho (where the company is located) and got it back within the week. I just covered the actuators where the module used to be with tin foil as I DD this bitch. Very detailed instructions on ModuleMaster's website, and I'd highly recommend. The dealer will give you a new module, but MM will rebuild one, and gives it a warranty. That way you know its sound.

 

Hey ObnoxiousDrunk, what all lights are on? Two or three? Because the abs goes into safe mode when there is a fault store in it and will not help with braking. So are your light in the insturment cluster on when the humm and vibranting noise happens?

O and I dont think your abs unit is bad. Because the wire that goes bad inside I believe is the power to the module. So if it was bad you would not get this braking issue.

Calmingstorm I think you maybe right about the wheel speed sensor being bad. I'm having problems with the left rear sensor. I have replace the sensor and checked the wires from the rear seat to the ABS unit, they were good. I did find that the ABS ring in the left rear was not install right and fixed that. The fault returns once a day, clear it and it will return the next day. When the fault comes back it turns off the ABS unit and turn on three ABS lights.

 

I only have the two lights (ABS and Brake). The thing is, when both these lights are on, the car drives fine, albeit without ABS (I have checked the ABS interaction in snowy conditions, and as I thought, the car slid, no ABS intervention).

It's only when both these light are out that the car experiences the issues stated above. It is very irregular, but has started to occur more often. I have also noticed that when driving for 15 minutes and making a stop (i.e. shutting off the car), the ABS and Brake lights go out and I know the car is going to have issues.

I have been told before that when the ABS goes is reverts to a default state and should not interact with braking. It only becomes an issue, like I said, when the lights go out. I really need to get the module out and look everything over.

For the time being, I pulled the fuse and will unplug directly at the module when I get the time.

 

Good looking out Kayakman...

I planned on sending the unit out when I get the chance to pull it. I have become complacent because I thought the issue was just it crapped out. But apparently my ABS likes to play games.