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 1998 Audi A4 owners, lightly cleaned up (personal details are redacted by NHTSA).
The airbag fault light and ABS light have been on ever since I had the vehicle, thinking that it May be a fault by the manufacturer as seeing very common problems in many websites. Another main concerned is the fault of the manufacturer's engine design causing engine damage from oil sludge. My concern is for future prevention measures.
The amber ABS warning light glows while the red brake light blinks. I understand newer Audi models have just been recalled for ABS issues, but my 1998 A4 was not included in the recall. Braking appears normal, and warning light illumination is sporadic.
ABS control unit on my 1998 Audi A4 failed as I was driving on the highway, total brake failure resulted, in which I was only able to stop via the triptronic transmission which allowed me to downshift, and finally using the ebrake...called Audi of America, they told me that their shouldnt have been total brake loss if the ABS unit failed, which made no sense since the pump was spewing brake fluid all over my engine...I assured them that it was a safety issue, and that Audi should be responsible for its repair, which runs in the range of $2500...they told me that that shouldnt have happened, and because of the high mileage on my car, they werent obligated to repair the problem, even though thousands of Audi owners have complained about the same problem...I believe Audi should be directly accountable for this mechanical defect, and issue a recall asap, before other Audi owners experience …
ABS control modules (Bosch 5.3) on all early model 98-01 Audi A4 and it's sister car the vw passat 98-01 will and do fail at some point. Control module is completely inoperative most times while driving. May start working sporadically and then quit again. Common problem on forums (audiworld.com). I have been a vw / Audi technician for 7 years now and have seen several of these. Would be nice to know that this safety feature is going to work when needed. Vw / Audi is aware of the problem and has just released a technical bulletin alerting that the control module May now be purchased separately from the hydraulic unit. This control module at my cost (considerable discount since I work for the company) is $1495.00. Please help myself and other Audi / vw owners get our cars stopping safely.
The ABS control unit on my Audi A4 failed after 95,000 miles. I have no anti-lock braking and Audi has denied any responsibility for the part since it is out of warranty. Searching through Audi forums I found this failure to be very common and everyone had no ABS until the control unit was replaced which cost an average of $1500+. There were no events that lead up to the failure, I started the car one day and the ABS and brake light started flashing on my dash. I tested the ABS and found that it indeed does not prevent my brakes from locking up. Nearly three years later, the part has not been fixed due to the high cost to repair it.
The ABS control unit on my Audi A4 failed after only 67,000 miles. I have no anti-lock braking whatsoever, and Audi has denied any responsibility for the part since it is out of warranty. Searching through Audi forums I found this failure to be very common and everyone had no ABS until the control unit was replaced which cost an average of $1500+. There were no events that lead up to the failure, I started the car one day and the ABS and brake light started flashing on my dash. I tested the ABS on an icy road and found that it indeed does not prevent my brakes from locking up.
ABS warning light intermittent. Research uncovered the fact that the ABS controller in the Audi and vw passat is faulty. Audi customer care has replaced the ABS controller for other customers. See this discussion thread http://tech.bentleypublishers.com/thread.jspa?threadid=3409&start=0&tstart=0. If this article\ad (http://cgi.ebay.com/ebaymotors/ABS-Bosch-5-3i-ABS-controller-repair_w0qqcmdzviewitemqqcategoryz111105qqitemz4601089179qqrdz1qqsspagenamezwdvw) is true and the problem is a cold solder joint then it is truly a manufacturers defect. Please investigate.
After only 65000 miles on my 1998 Audi A4 I have been forced to replace major ABS components because of numerous failures. The ABS system works intermittently, and there is no indication of when it will fail. A brake light will come on, then go off, indicating there is trouble, but at times the light will be off and it is not until you begin to brake that you realize the ABS is non-functional. Audi has been very slow to repair the problem, requiring a 2 week wait just to diagnose the issue. Then requiring $2300 to make a 6 year old car safe to drive.
ABS light comes on intermittently and ABS system is not functional. ABS system also used in electronic differential control. Audi dealer diagnosed as a ABS control unit failure with part cost of $2600 plus labor and was repaired by Audi dealer. Contacted Audi customer care and they did not offer any assistance. This is a very real safety issue and based on internet searches has affected hundreds of Audi and vw vehicles. This appears to be a faulty design of a critical safety component and warrants further investigation.
Out of nowhere, ABS light on, brake light flashing. Took to shop, they stated this is a common problem for the ABS module to lock out communications; 1400 + for the repair. This is an expensive car; I find it outrageous the electronic module is outside, subject to weather conditions and salt. Please see my complaint on coil springs as well. Researched the problem on the internet and it seems this is usual and customary for this model, I feel NHTSA needs to step up here and call Audi on the table.
Related recalls
Service brakes, hydraulic › Power assist › Vacuum › Hoses, lines/piping, and fittings
Vehicle description: passenger vehicles equipped with automatic transmissions. A control valve in the vacuum hose connecting the brake booster to the intake manifold May not open or close fully at temperatures below -4 f under certain driving conditions.
Remedy: Dealers will install a vacuum by-pass system into vehicles operated in these states which is designed to provide sufficient vacuum for full brake assist under all weather conditions.
NHTSA investigations
Power brake booster vacuum by-pass
There is no summary currently available
Brake and clutch pedal bracket
Degraded braking in wet weather
There is no summary currently available
Brake complaints in other A4 years
Frequently asked questions
How common are brake problems on the 1998 Audi A4?
NHTSA has 125 complaints about the brakes of the 1998 Audi A4, 48% of the model year's 258 complaints. The component named most often is antilock/traction control/electronic limited slip (59 mentions).
Is there a recall for 1998 Audi A4 brake problems?
Yes — NHTSA recall 99V131001 (hoses, lines/piping, and fittings, May 21, 1999). Recall repairs are free at authorized dealers.
At what mileage do 1998 Audi A4 brake problems start?
Half of the complaints with a recorded mileage happened before about 86,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 3 injuries 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.