One problem related to ignition module has been reported for the 2003 Audi A4. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Audi A4 based on all problems reported for the 2003 A4.
In 1/04, during normal driving conditions one evening, my '03 1. 8t A4 began shaking violently as I began accelerated from a stop sign. The check engine light came on and I lost a significant amount of power and couldn't accelerate well. The dealer stated that I blew an ignition coil. Not 2 months later, in early 3/04, the same exact situation occured and I had to have another ignition coil replaced. I have learned that the mfr had a product recall for this exact problem, however my vehicle's components are not covered by those under recall. I was told I have the "newer" versions of the igition coils already in my car. While they might be newer, they sure haven't solved the underlying problem! two blown igition coils in less than 2 months and I can't get the mfr to replace the other 2 coils that I'm certain will go out at some point soon too.