Did you try borrowing a old Snap On MT2500 to see if it can pull the Airbag codes like I need to do for old Dodge Durango ABS ,or at least unplug the antilock brake module with the VIN mismatch? Have you considered possibility  that if there is  any sort  VIN mismatch code it could  red flag  it to prevent any further communication with an Airbag system for liability concern of accidental deployment ?
  If the old Snap On scanner works and the DS708 still does not pull the codes, even  after unplugging ABS module and retry. I would figure it is another old Chrysler software hole that Autel never did or never will fix, no matter how many data logs people send in.
 JClaus98 , I bet it could pull your brother's airbag codes  on his Red Mercedes up at the North Pole though :-))
 

   Well I have a MT2500 for OBD 1 cars and older OBD2 through 2005. I always first  grab DS708 , and noticed some software holes or communication issues with some  older Chrysler products too but I think it is overall a great tool that  has served me well since August 2013. Other than being slower than the Maxi Sys , not having J2534 , no one has of yet given me a concrete list of  functional  examples of advanced coding that I am likely to miss on cars here  in the USA that a MS 905 Mini offers (that will actually work) where it is not also  found on my DS708 , unless newer Autel updates intentionally removed and dumbed down it's Former Flagship DS708 in recent years in order to list DS708 coding functions as minimal, but Autel denies removing any software functions.
  I have compared Software Version Updates numbering and noticed since my expiration that some makes numbers like Chrysler since mid 2014 have only gone up just one /one hundredth of a decimal point , ex  Chrysler version went from V 7.10 to only V 7.11 in over 2 years, so maybe something court ordered had to disappear. Probably still no new car coverage added since 2014
  Ford only went from V9.00 to V9.13, one tenth of a decimal point,plus three hundredths of a decimal point, so maybe one thing got fixed or reappeared, while 2 other things disappeared? Again probably little new car coverage added .
GM software went up a whole number from V10.00 to V11.20, so I figure they actually added another full year of new vehicle coverage, and maybe  a couple things came back and got repaired? Who knows the method to their madness?
  Of the car makes I would  "likely to see in the USA" that had a DS708 update that the update version number actually increased by one whole number or more since mid 2014. (Audi, Bentley, GM, Hyundai, Infiniti, Jaguar, KIA, Land Rover, Mini, Mitsubishi, Nissan, Rolls Royce (appeared), and Volvo (Volvo did shoot up over 3 whole numbers versions ,like you would have expected the rest of the makes to have done in two and a half years of updates  LOL )