Which parts fail
Components named in complaints (service brakes, ABS, rotors and pads, parking brake).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2000 Audi S4 owners, lightly cleaned up (personal details are redacted by NHTSA).
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. …
Many Audi and vw models manufactured starting in the later '90s and continuing to present, use the Bosch 5.3 ABS controller, which is prone to catastrophic failure, ostensibly due to defective design. This module controls multiple brake-related functions including the ABS which is important for winter driving, but the most critical function of this module is probably the electronic brake force distribution, or ebd. These vehicles are designed such that if the ebd is inoperative, the proportion of hydraulic force applied to the rear brakes during emergency braking is as great as it is during moderate braking effort when there is minimal transfer of vehicle weight to the front wheels. The ebd is supposed to adjust the front/rear braking distribution dynamically according to the measure of the deceleration, so that the rear wheels will not lock up during emergency braking. …
Purchased my 2000 Audi S4 from the original owner- the car had 10K miles on it and yes, it was out of warranty. At about 13.5K miles I noticed that I had trouble stopping one evening- almost rear ending someone in the process because my brake pedal went all the way to the floor. Parked the car that night-and then about 4 hours later, on my way home...same symptoms as mentioned before, except now my ABS light was on. Ext mourning...moved car out of driveway and noticed a oil puddle from the left front drivers side engine area. I began to search for the leak with the help from a local friend and he suggested-last resort-to check the ABS control unit...I did, and sure enough, my whole hand was covered in oil when I reached underneath the ABS unit. Called local Audi dealer...and also called Audi of America...dropped car off at dealer...they confirmed that the unit (ABS) had indeed failed. …
Complaint received via e-mail." I purchased a 2000 Audi S4 quattro with 39K miles on it from a non-Audi dealer in March of 2002. At approximately 50,600 miles my ABS controller failed. This is indicated by a diagnostic trouble code (DTC) in the vehicle's ECU (computer) as well as 3 loud beeps when you start the car and the ABS light staying lit and the red brake light flashing constantly. This part has failed on multiple Audi S4's of the same model year that I know of. Audi would not warranty my part as my factory warranty had expired at 50,000 miles. The parts alone cost approximately $1200 plus the additional cost of the labor to install the part. The results of the ABS controller's malfunction is that essentially, I do not have anti-lock braking in the car, causing under hard braking the possibility of locking the brakes. This happened on numerous occasions. …
Out of the blue, with 64,000 miles on the car, the ABS warning light and brake warning light come on, followed by 3 loud beeps. When the beeps stop, the ABS warning light stays on, the brake warning light blinks continually. Since the first incident, this now happens every time I drive the car. Sometimes the lights will go out and stay out for 5-10 minutes, for the whole thing to start over again. When these lights are on, the ABS does not work. I had a panic stop to avoid a deer and the rear wheels locked up. The car skidded but I did not crash. Dealer says that the ABS controller computer must be replaced, at a cost of $1300. This is apparently very common on 2000 S4 and a4 Audi's. I contacted Audi of America, they refuse to fix the problem, denying that it is a safey issue and saying that the car is out of warranty.
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.
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!
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
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 (~$1700.00), even though the most likely culprit of the problem is wiring between the controller and the ECU (<$1.00).
Driving on the on-ramp, about 40 MPH. I was cut off fairly aggressively and had to apply the brakes hard. My brake light lit-up and beeped a few times. My car then began to spin out of control across the freeway (I-40, a major trucking artery). Luckily I did not hit anyone and was able to control the spin. I found out later that my ABS control unit (what a surprise) failed, of course at the most critical time of need for it. Total cost to replace was $800. Audi , in spite of numerous complaints about this part on this car, will not take any responsibility for recalling or reimbursing.
Brake complaints in other S4 years
Frequently asked questions
How common are brake problems on the 2000 Audi S4?
NHTSA has 41 complaints about the brakes of the 2000 Audi S4, 29% of the model year's 143 complaints. The component named most often is antilock/traction control/electronic limited slip › control unit/module (15 mentions).
Is there a recall for 2000 Audi S4 brake problems?
No. NHTSA lists no brakes recall for the 2000 Audi S4, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2000 Audi S4 brake problems start?
Half of the complaints with a recorded mileage happened before about 67,000 miles, and 3% before 25,000 miles.
Is it dangerous?
Owners linked 3 crashes, 0 fires and 1 injury to brakes problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.