One problem related to ignition anti-theft immobilizer/proximity sensor has been reported for the 2011 Hyundai Sonata. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2011 Hyundai Sonata based on all problems reported for the 2011 Sonata.
The contact owns a 2011 Hyundai Sonata. The contact stated that after the manufacturer performed service campaign 993 (inspect & anti-theft software upgrade) the vehicle failed to shutoff as needed. Additionally, the alarm was activated while starting the vehicle. The contact disconnected the battery to shutoff the vehicle. The vehicle was taken to the dealer, where pliers were used to remove the key fob and a second key was used to restart the vehicle; however, the failure recurred. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 112,000.