My name isXXXXX will try to help you.
There is several TSB (Technical Service Bulletins) from Hyundai for stall during driving TSB's for Automatic Transmission TSB# XXXXX TSB#07-40-007 TSB#09-AT-008. Your dealer have to perform testings and diagnostics. Also there is software updates for Engine and Transmission Computer's but depending on engine Code information. Is there any Codes stored in Computer, you can go to your local Autozone and have them scan your car usually at no charge, if any code present in memory when car stall I would need this code data in order to take a look what has to be check or perform to repair.
Please let me know.
Yes, but if they change battery prior to diagnostics, the code would be erased by doing so. Also the TSB's # XXXXX provide you in prior message from Hyundai in regards XXXXX XXXXX while driving and there is several revision of TSB's in regards XXXXX XXXXX malfunction in AT (Automatic Transaxle).
There is also TSB from Hyundai for Voltage drop with same explanation of your problem for headlights dim TSB#08-BE-004 there is also steps for diagnostics.
I will look more information for you but call your dealer and ask about TSB 08-BE004 because there is ground problem repair steps in that TSB as well as wiring repairs and diagnostics.