Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2003 Audi A4 owners, lightly cleaned up (personal details are redacted by NHTSA).
The coolant light came on after I replaced coil packs and I stopped to look wasn't leaking anywhere. Drove to work and it caught on fire due to overheating I guess not really sure. I was driving a car on fire down a highway and didn't even know it. I stopped to take a left turn into work and smoke stared billowing out and around the entire car. Other drivers couldn't see me or nothing I could have been in an accident. The fire department checked the car out sort of and it's in a mechanics shop now. Trying to figure it out. Oil light was on and that's it. AN then the coolant light would kick on and off. Nothing else after I changed the coil packs. And it was well after I did that.
Initially drove car home from grocery store hit a bump and noticed a spark coming from front driver's side of car. Pulled over and checked for spark evident once stopped there was no sign of spark or anything. Got car home and parked about an hour later my car was on fire, after putting the fire out my husband lifted the hood and tried to investigate the issue when he discovered the battery was melted to the hood and is where the fire initially caught. The location of the battery we believe to be the issue and wanted to make sure to report it immediately.
Forgot to install c clip on temp sensor on radiator hose which popped out causing major engine damage and blown head gasket which was denied for many months. In oct. 08 they forgot to tighten bracket which caused wires to smoke and fire.aug 08-trimmed serpentine belt rather than replaced and car stopped running in middle of interstate. Sept 09 replaced oil pan but forgot to put plug back oct 08 oil residue on damper they threw out and did not replace. They forgot to put bolts back on sub frame and miracle I was not killed. This caused axle problems. When they replaced bolts they did not have bushings in stock and they released car without these bushings which is a safety violation. When bushings came in they refused to work on our vehicle and we had to go to different mechanic. They told us we needed timing belt when the headgasket was blown. …
After returning home from a drive through fast food place last night my daughter was parking in our driveway, she was in reverse. The car (a 2003 Audi A4 cv convertible) bounced and made a sound then she stopped. I said take the keys out of the ignition to her black smoke started to rise out of the top of the hood crack in front of the front windshield. I told her to get the dog in our back seat and herself out I assumed it was on fire because the dark smoke. I grabbed my purse piped the hood and my daughter called 911 as the neighbors ran inside there home for a fire extinguisher. Two men from across the street attempted to put it out as I spoke to the 911 operator. The fire department arrived and got the fire out. My car is now junk. My daughter was emotionally strained, hysterical throughout the incident. It was traumatic for us both. …
Tl* the contact owns a 2003 Audi A4. The contact stated that while driving at 35 MPH, various electrical functions of the vehicle shut off and the steering wheel seized. The engine warning light illuminated. The failure occurred once. The vehicle was taken to an independent mechanic where it was diagnosed that the transmission control module needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 200,003.
Radio intermediate goes out hitting bumps speedometer stopped working the number ninth digit is not pulling up when I search vehicle information Replaced engine vehicle only had 20,000 miles
Left turn signal works fine. Right turn signal alternates between flashing left and right.
Water pump failed inside lights sometimes work and signal lights aren't accurate
I purchased this car on 1/24/07 with 22,422 miles on it. Six days later the engine light was flashing, it was shaking unbelievable, would not run properly, go over 20 MPH. I returned it to the dealership I purchased it from, they replaced a coil pack. Within a short time, on February 14, 2007, the engine light had come back on. At that point I brought it to the nearest Audi dealer. It needed a turbo bypass valve replaced. Friday, March 9, 2007 the engine light had come on again. I brought it to the Audi dealer once again. They reset the engine codes and say it has had a random misfire. Today, March 11, 2007 the engine light is flashing again, and will not drive over 20 MPH. I am having it towed to the dealer in the morning, today is Sunday and they are not open for business. I drive about 1,000 miles a week and I need my car operational. …
On three separate occasions my 2003 A4 (1.8t) started shaking violently as I accelerated from a complete stop. Every time it happened the check engine light came on, the car lost most all of its power and was difficult to steer, and wouldn't get above 15 MPH. And every time it happened I was stranded in the middle of traffic, having to coax the car over to the side of the road and out of harm's way. The car was towed each time to the dealership where I was told that an ignition coil (or two) had blown. All 4 coil packs had to be replaced within a year at a cost of over $900. Audi knows they produced cars with faulty ignition coils in A4 cars equipped with 1.8 liter engines in the 2001, 2002, and early production 2003 model years. In February 2003 they announced that they would replace these coils free of charge to the vehicle owners. …
Electrical complaints in other A4 years
Frequently asked questions
How common are electrical problems on the 2003 Audi A4?
NHTSA has 32 complaints about the electrical system of the 2003 Audi A4, 15% of the model year's 210 complaints. The component named most often is ignition (12 mentions).
Is there a recall for 2003 Audi A4 electrical problems?
No. NHTSA lists no electrical system recall for the 2003 Audi A4, though it has 3 recalls 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 2003 Audi A4 electrical problems start?
Half of the complaints with a recorded mileage happened before about 57,000 miles, and 12% before 25,000 miles.
Is it dangerous?
Owners linked 0 crashes, 4 fires and 1 injury to electrical system 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.