Odd issues possibly around S3 ABS and ESP

[Perplexer]

Hi all,

2002 S3 BAM. I had a recent issue where the ABS and ESP lights would stay on. Used my ebay version of VAGCOM and it came up with the right rear ABS sensor. My mate has a garage and he also read the same error on his Snapon setup, replaced the sensor and cleared the fault. The lights didnt return.

But whenever I am slowing down (either braking or just coasting) and the speed is between 5 to 10 MPH (maybe a little less) I can hear an electrical buzz that sounds like a relay operating rapidly and it changes in speed in relation to me slowing down. This sound was present before I had the sensor replaced but I just didnt notice it as much. Nothing comes up on VAGCOM.

This morning I got in the car to go to work and the buzzing was still there when slowing down. When hitting the first roundabout the ESP flashed on a few times and I lost power to the engine a little, so I turned around and came home (I am lucky as I can work from home).

I have done a search but couldn't find anything around the buzzing sound. Could anyone please help with any of the above? Much appreciated, although I am sure my wallet is goin gto take a kicking with this...

 

[Dane]

Sounds like the abs pump, if your in the drivers seat does it sound like its on the left and lower down?

 

[Perplexer]

Sounds like the abs pump, if your in the drivers seat does it sound like its on the left and lower down?

Thanks for the response.

Yes it does. I couldn't quite pinpoint it as I was assuming it was from the dashboard, but the sound does come from the left lower area of the car.

What is the deal with these? Expensive to fix/replace? Would this contribute to the ESP issue?

 

[Dane]

It seems odd theres no fault code, how does it feel to drive does it feel a bit sketchy under braking, does it lock up easily etc?

I have a problem with the wiring to my lhs abs sensor, I could hear my abs pump working when I was just steering at very low speeds with no brakes. After an easy journey down the motorway to Welly's the wheels were hot and there was a very apparent smell of brakes dispite being very gentle with them. We decided to pull the abs fuse to stop it working all together which made the car alot easier to deal with and much more predictable until it gets fixed.

A fix for the problem needs help from some one waaaaaay more knowledgable than me I'm afraid.

 

[Perplexer]

Seems ok to drive and ABS does work when braking hard.

Thanks for the help though

 

[Perplexer]

What I have noticed is that the brake pedal hisses when pressed and feels a little spongey (car sationary but running) - could this be anything to do with it? At the last service I had the brake fluid changed.

Edit: placebo. Nothing wrong with the brakes.

 

[Perplexer]

Ran vagcom again and now it is saying there is a mechanical failure on the same one that was replaced. My garage says it is looking like the ABS ECU as that is where the sound is coming from and him seeing the same issue on 3 other Golfs. Looking at £350 + VAT for the repair of the ECU.

 

[thegoal007]

£350 for the ecu repair ? Who is going to repair it - are they going to send it to a specialist company for repair (1-2 week turnaround) ? I know for a fact a new one of those is just under a grand. Are they going to simply swap it for a refurbished one or repair yours ?What happens if you get it back and still have the same problem ?
google your problem thoroughly. Try and get a friend outside of the car to try and gauge where the sound is coming from...if poss. Do you get the sound if you drive off and stay slow - up to 10mph ? or is only when coming down off speed to 5-10mph ?

Also I don't think you need to worry about the break pedal expeirences you are having.

 

[Westy]

Before you shell out for a new pump check the sensors with VCDS.

I had the exact same issue you describe above with no errors in VCDS and no dash lights illuminated. It turned out that one of my sensors that was a Euro Car Parts sensor was causing the issue below 5mph. I swapped it out for a genuine Audi sensor and it fixed the problem.

In VCDS go through the measuring blocks for the ABS pump and one of them will display all 4 wheel speed sensors. As you're going along the numbers should go up for each sensor depending how fast you're going. All 4 should be identicle or as close as. Drive around for a bit recording these numbers and include some stopping/slowing so you can get the pump to cut in as you describe.

If you then look over the recoreded spreadsheet you should be able to spot which sensor is the one at fault.

 

[Perplexer]

£350 for the ecu repair ? Who is going to repair it - are they going to send it to a specialist company for repair (1-2 week turnaround) ? I know for a fact a new one of those is just under a grand. Are they going to simply swap it for a refurbished one or repair yours ?What happens if you get it back and still have the same problem ?
google your problem thoroughly. Try and get a friend outside of the car to try and gauge where the sound is coming from...if poss. Do you get the sound if you drive off and stay slow - up to 10mph ? or is only when coming down off speed to 5-10mph ?

Also I don't think you need to worry about the break pedal expeirences you are having.

Thanks for the response. There is a specialst ECU repair outfit in Nottinghamshire - I do not have the details yet. They would repair my original one for £350 + VAT but will run a diagnosis on mine before for £40 (this would then come off the repair). It should be turned around in 3 days and have a 12 month warranty.

The sound only happens slowing down and starts below 10 MPH, closer to 5 to be honest and it stops when I stop.

 

[Perplexer]

Before you shell out for a new pump check the sensors with VCDS.

I had the exact same issue you describe above with no errors in VCDS and no dash lights illuminated. It turned out that one of my sensors that was a Euro Car Parts sensor was causing the issue below 5mph. I swapped it out for a genuine Audi sensor and it fixed the problem.

In VCDS go through the measuring blocks for the ABS pump and one of them will display all 4 wheel speed sensors. As you're going along the numbers should go up for each sensor depending how fast you're going. All 4 should be identicle or as close as. Drive around for a bit recording these numbers and include some stopping/slowing so you can get the pump to cut in as you describe.

If you then look over the recoreded spreadsheet you should be able to spot which sensor is the one at fault.

Thanks for this. The car was on the test kit in the garage today. We drove the car and only 3 sensors were picking up speed readings. The one that was replaced was not. It is a genuine Audi sensor fitted and there are no lights on the dash.

 

[Westy]

Thanks for this. The car was on the test kit in the garage today. We drove the car and only 3 sensors were picking up speed readings. The one that was replaced was not. It is a genuine Audi sensor fitted and there are no lights on the dash.

I also had that when fitting a sensor myself. I went back to it and it turned out that I hadn't pushed it in close enough to the little speed wheel that the sensor reads. Check that the sensor is as close to the wheel as it is on the working sensors.

 

[Perplexer]

I also had that when fitting a sensor myself. I went back to it and it turned out that I hadn't pushed it in close enough to the little speed wheel that the sensor reads. Check that the sensor is as close to the wheel as it is on the working sensors.

Will do - cheers.

 

[Perplexer]

I also had that when fitting a sensor myself. I went back to it and it turned out that I hadn't pushed it in close enough to the little speed wheel that the sensor reads. Check that the sensor is as close to the wheel as it is on the working sensors.

Sorry for the lack of updates - busy week or so...

I ran VAGCOM again to see if I could get a reading and it came up with this:

00285 - ABS Wheel Speed Sensor Rear Right (G44): Mechanical Malfunction

At this point there was no reading from this sensor when the car is in motion (other 3 were reading fine).

Looking here (00287 - Ross-Tech Wiki) gave this:

Possible Causes
Excessive Air Gap between ABS Wheel Speed Sensor Rear Right (G44) and Rotor
Short Circuit in Wiring from/to ABS Wheel Speed Sensor Rear Right (G44)
ABS Wheel Speed Sensor Rear Right (G44) faulty

Possible Solutions
Check ABS Wheel Speed Sensor Rear Right (G44) Installation
Check Wiring from/to ABS Wheel Speed Sensor Rear Right (G44)
Check ABS Wheel Speed Sensor Rear Right (G44)

So the new sensor fixed the lights on the dashboard but it just wasn't picking up a signal from the wheel. I had the garage refit the sensor - upon inspection he found some copper grease contamination. After cleaning and refitting the sensor and testing I no longer get the buzzing from the ABS pump and the car seem to be driving normally!

Hopefully this is resolved. Thanks to all of you who commented on this thread - I really appreciate your help

 

[Westy]

Glad you sorted it

 

[Perplexer]

Glad you sorted it

Cheers for your help. Hopefully it stays fixed and I don't have to splash out a load of cash.

 

[thegoal007]

sounds like money's burning a hole in your pocket.......what rescession !

spend it wisely.