One problem related to air bag on-off switch has been reported for the 2005 Audi A4. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2005 Audi A4 based on all problems reported for the 2005 A4.
2005 Audi A4 quattro was serviced at dealership in nashville TN for a recall of coil packs. Afterward the air bag warning light appeared. The car was serviced for the air bag and a switch under the seat was replaced at my expense. Two weeks later the air bag light re-appeared. The dealer states that a new sensor is necessary. A search on the internet revealed that many Audi owners are experiencing problems with the air bag sensor. This is a defective safety part and should be recalled by Audi.