1998 Audi A4 Quattro 2.8L V6 30V (B5 platform, 8D)

I am trying to test that my ABS is working okay, based on a mysterious instrument cluster bell which rings randomly while driving.

When I open control module 3 in VCDS, the ABS light comes on and the brake light blinks. If the engine is running when I open the module (or, if I start the engine while the module is open), I hear the alarm ring three times. Sometimes, however, the alarm won't sound until I press and release the brake a few times with the control module open while the engine running (haven't ever heard it sound when the engine isn't running) I cannot cause the alarm to ring at will when VCDS doesn't have the control module open. No fault codes are recorded at any time (before or after the alarm rings) Is this all normal?

Address 03: ABS Brakes
Control Module Part Number: 8E0 614 111 M
Component and/or Version: ABS/EDS 5.3 QUATTRO D31
Software Coding: 0273004134
Work Shop Code: BB 24302

No fault code found.


Furthermore, while using the measuring blocks and logging groups 1,2, and 4 together and driving the car, sometimes the alarm sounds instead when the measuring blocks are open and the car starts to move. The ABS module data feed from the speed sensors, however, is all normal on all 4 wheeles and the readings continue to be received until the car reaches 20 km/h, at which point the ABS modukle drops them off, as per the manual.

Finally, I've opened Output Diagnostic Mode and gone through the steps, however without yet lifting the wheels off the ground and checking if they actually lock and unlock correctly. The Hydraulic pump runs and sounds and feels fine, the valve seems to be functioning correctly.

Based on all of this, is there any indication that the warning bells I'm hearing from the instrument cluster while driving are an indication of something wrong with my ABS/EDL system?