Summary
The Audi A4 has 23 recalls spanning 1996 through 2022, with the most serious recent issue affecting 2022 models where a semiconductor in the engine control unit can short-circuit, causing the engine to stall unexpectedly and raising the risk of a crash.
The 2017 through 2020 model years have a passenger seat sensor that can malfunction and disable the front passenger airbag even when someone is seated, with the instrument panel displaying a "passenger airbag off" warning. On 2017 models, aluminum trim around the door speaker covers can work loose and expose sharp edges inside the cabin. Going back to 2013, two separate issues affect that model year: a coolant pump blockage on vehicles equipped with the 2.0L TFSI engine that can cause the pump to overheat and start a fire, and an airbag control module with incorrect coding that can prevent the front airbags from deploying fully in a crash.
The 2004 through 2009 model years carry Takata-related passenger airbag inflator recalls. These inflators can rupture during deployment, sending metal fragments into the cabin. Vehicles originally sold or registered in high-humidity states and territories face the greatest exposure to this risk. The 2003 model year has a driver airbag igniter that may not have been properly seated during assembly, preventing the airbag from firing in a crash. The 2000 through 2002 model years have a driver airbag inflator that can fail to protect the occupant in a crash due to moisture absorption, and the 2000 model year has an additional driver airbag moisture issue filed separately.
On 1997 and 1998 models, a driver airbag inflator can absorb moisture over time and either explode during deployment, sending metal fragments toward occupants, or underinflate and fail to cushion the driver. The 1997 model also has rear seatbelt retractors that may not lock properly, reducing occupant protection in a crash. Going back to 1996, the ignition switch housing can crack at the return spring anchor point, leaving the key stuck between the start and run positions after engine startup and disabling accessories like headlights and windshield wipers. That same model year also has an intermittent horn caused by insufficient electrical ground contact. The 1998 model year has an air intake screen that can break apart during a cold-start backfire, with fragments potentially jamming the throttle plate open above idle.