Some 2016 MKX and 2017 Continental/MKZ vehicles equipped with a Revel Ultima audio system may exhibit a loud screeching/squealing noise from the speakers when the audio system is on or off. To determine if the vehicle is equipped with a Revel Ultima audio system access the window sticker through the Historical Vehicle Bill of Materials on the Professional Technician Society Website. Under optional equipment the audio system will show up as Revel Ultima, Revel Ultimate, or Revel II Audio. To correct the condition, program the digital signal processing (DSP) module to the latest calibration using IDS version 102.03 or higher. Make sure you are connected to the internet when entering module programming to obtain the latest calibration. Use causal part 18B849 and applicable labor operations in section 10 of the SLTS manual.
