Two problems related to ignition module have been reported for the 2002 Audi A4. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2002 Audi A4 based on all problems reported for the 2002 A4.
My 2002 Audi A4 1. 8t had a coil pack failure on 12/18/02. The failure caused the car to sputter lose speed and become unpredictable. It occured at a speed of 30 mph forcing me to take evasive driving action. Upon further research, I found out that this failure is occuring on a very large scale with dozens and dozens of 1. 8t engines (both vw and Audi) having this problem. Vw/Audi has not issued a recall for these parts and is only replacing the failed part. There are coil packs in each 1. 8t. Vw/Audi is not acting on this problem leaving thousands of 1. 8t owners with defective parts in their cars. When a coil pack fails it is a very dangerous situation.
The car's basic problem is a badly designed coil pack (ignition module). There is a redesigned one but the dealer will only replace the one that fails. Leaving three others (in a 4cyl car) to fail at a later date. These failures happen mostly at engine startup, but has also happened to me at the worst possible time also. Like driving in a tunnel where there is no shoulder to pull off to. The engine just cuts off like someone reached over and turned the key. . . Luckily when this happens at speed in a manual trans. Car, I just popped the engine back on. Dt.