2000 Audi S4 with unreadable gauge and warning lights on the instrument cluster. Consumer states this has gotten worse and they are not readable at all. His brake pedal was soft and the warning light was unreadable. While driving, there was a loud beep followed by a constant flashing of a blurry display which the consumer could not read. The consumer later discovered the flashing light was suppose to show the brake level signal/pad signal level. The vehicle was towed to the dealer where it was determined that the ABS pump had failed.

- Shoreline, WA, USA

ABS warning light on dash, accompanied with a flashing brake warning and three beeps. This occurred intermittently and with increasing frequency. Based on some invcestigationg, this appears to be a very common problem with the ABS controller modules on Volkswagen and Audi vehicles. When the module fails, it renders the ABS system inoperative and can lead to rear wheel lockup in emergency stopping manouvers or in slippery road conditions. I have removed the module and had it repaired. This service at an Audi dealer would cost in excess of $1000.

- Los Altos, CA, USA

Posted comment earlier about battery acid leaking onto clutch line and brake line causing severe damage to both lines... spoke with Audi and they stated that the engine does not have to be removed for the brake line to be fixed... the most likely culprit of this leak is due an overcharged battery due to a jump or manual re-charge (note: According to Audi, never replace the S4 battery with anything other than with an Audi battery... of course they would say this, but he was pretty convincing... 2nd note: I do have an Audi battery in my S4, and I'm still having the issue... Audi may help pay for this B/C of that fact, but they haven't committed to it until further investigation). The total, according to over-the-phone diagnosing, was going to be B/N 1 and 2 thousand bucks at the dealer.

- Albuquerque, NM, USA

My ABS and brake lights come on irractly while driving. I have checked the and filled the brake fluid resivor like the manual states. But still get the lights. Apparently this is a very common problem from Audi. The saftey of many people are at stake here. I will not and have not driven my car since the lights came on, and my local Audi dealership want $1,400. To replace! thas ridiculous for a car that has barely 54K miles. You would think something as important and life saving as the brake system would have a better design and lower failure rate. Im positive that I am not the only Audi owner that has filed a complaint and postive I will not be the last. Thank you for you time luis castellanos

- Silver Spring, MD, USA

While driving the brake and ABS lights came on. The owner took the vehicle to the dealer and was told by the dealer that this defect can cause the other controllers to do damage and effect the instrument cluster. It can also effect the engine controller. The owner also contacted the manufacturer who did not think that this problem was of needed interest. Provide further details.

- San Jose, CA, USA

My ABS controller appears to be failing. ABS warning light will come on and go out at random times. I have 48,000 miles on this vehicle. Since the ABS system acts as a proportioning valve between the front and rear wheels, the rear wheels will lock up under moderate braking when the light comes on. I cannot diagnose the problem properly due to the random nature of the warning light. Many similar reports on audiworld.com on this failure.

- Mableton, GA, USA

Failed ABS controller unit. ABS is nonfunctional. In poor weather, my brakes will lock up.

- Richardson, TX, USA

The ABS and brake lights on my dashboard initially flashed and beeped intermittently, but now are on constantly. Upon researching the issue, I've discovered that this is a problem experienced my many other MY2000 S4 owners. This is a significant safety issue, as there is the risk that brakes may lock up (even when releasing the pedal) under braking when experiencing these symptoms. Please take action on this issue. I know many owners who have no choice but to hold off on the repair due to the amount being charged by dealers to replace the part (~$1700), even though the most likely culprit of the problem is wiring between the controller and the ECU (<$1).

- Chicago, IL, USA

ABS controller module failure - Bosch 5.3 system - 2000 Audi S4.

- Mystic, CT, USA

Problems with ABS controller on 2000 Audi S4. ABS warning light was intermittently on.

- Portsmouth, NH, USA

While applying the brakes pedal went to the floor. Consumer was able to maintain control of the vehicle, and drove it home. ABS braking light appeared on the dashboard and remained on. Consumer contacted the dealership, and will make appointment to bring the vehicle in for inspection. Consumer contacted manufacturer but refused to assist repair of vehicle.

- Somerset, NJ, USA

On or about 11/20/00 I applied brakes while driving down hill. Car accelerated out of control. Brakes would not stop car, which eventually crashed into telephone pole. I injured my left leg. Audi advised me they knew of no "defect" that could cause this accident. On 13/21/01 as I applied brakes to turn into a parking space contiguous to a building the vehicle accelerated. When I both heard to engine racing and the car accelerating I fortunately shifted into neutral and stopped the vehice. My foot was not on the accelerator! I refuse to drive this vehicle. Audi's response is that if the dealer finds a problem Audi will take appropriate action. There is a problem whether Audi finds it or not. I am not risking a fatal accident to establish this fact!

- Dorset, VT, USA

Audi usa has engineering control and were contacted and present during repair. Under very icy conditions on straight road, during acceleration from very slow speed, vehicle pitched into oversteer condition. Not entirely unexpected, but after a difficult recovery, when all seemed ok, it oversteered again quite violently. This was again recovered, but it appeared that there was an ABS brake input, certainly not of my doing. The third cycle was more severe, and I left the road. Neither the brake nor throttle were touched during the whole cycle, but steering inputs were powerful as I attempted to save the day. The separateness of the cycles alerted me to the possibility that the wheel speed sensors had detected a differential speed and applied the brakes. Audi refuses to release any data on the operation of their ABS system, and the volatile computer data has gone..it is noteworthy that some of the control functions previously identified, electronic stability control, etc, are now embedded in the ABS. The S4 did not have a stability control mechanism, it now does. This is a very powerful vehicle system, and if it should fail, the consumer should be able to know the criteria under which it should, could operate and/or fail. A years worth of communication has produced zero data from Audi.

- Naples, FL, USA