Random ABS warning.

[carbore]

I had an ABS fault a bit like this on a Mk3 Golf 20ish years ago, ironically its where I first use "Vagcom" as it was back then and bought the cable I now use on the A2. Anyway, The issue was an ABS sensor. Whilst the diags did not show the sensor as a specific fault they DO allow you to show wheel speed as you drive. I drove around with laptop on and low and behold I could see erratic/zero wheel speed on one side. Replaced the sensor that side and it was fixed.

I also found out you can put a multi meter over the sensors oh Ohms and see a reading, I cant remember the correct reading, but one read a sensible value and the other (broken one) was I think a dead short.

My fault manifested its self as intermittently the ABS light would come on and intermittently ABS would come on when breaking gently. Effectively the sensor was showing the wheel as locked so it "buzzed" the ABS on that side.

 

[Sylvester]

I'm hoping to either get across to @Erlingtheyounger for a scan, or to get a lead and use VCDS Lite myself. I will report back. The knocking does sound very similar to what you describe. Was it easy to sort the yaw sensor?

It's not difficult to change it, but I still haven't as the symptoms had disappeared after a few scary days. There was no fault code when restarting the car, brakes looked good, so I just moved on to the next thing. The reason I didn't see fault codes, as I didn't do a full scan, just an engine code check, and the fault codes actually were stored in the abs system.

But nearly 2 month ago, on my way to the airport after 3am, it reminded me again, by flashing the dashlights 5 miles away from the airport, I was not happy , but fortunately my A2 got me there without any futher issues, so I was really thankful for that I did a quick scan before locking the car up at the airport, and it showed the intermittent yaw sensor fault. On the way back it came up again, but I knew what was causing it, so I just carried on, looking at the flashing dashboard for 1.5 hour wasn't fun though. Fortunately apart from that, it drove really great Both ways it was just 1 shake, unlike over a year ago, when the car was shaking violently every few seconds at some point, so I know how you must've felt

To change the yaw, just remove the kick-panel from passanger side and some foam in the way, then just unplug it, it's a bit awkward to reach, but doable.