Both Jeep and VW use the ISO9141 interface standard. (this applies for sure to CRD's and later XJ's. no experience on gas KJs) If your CRD is on the list for F31 that was caused by a earlier flash you'll need it
Anyone with a vag-con reader that will run the current software, not the original opto coupler version, can read their firmware version and more using vag-com's OBDII mode option 9 for "vehicle information. It gives the VIN and controler numbers along with a verification number for address 12 and 41. The numbers for address 12 match closly my TCM and 41 matches closely my ECM.
In addition under obdii > READ DATA there are 9 as I recall different things that can be monitored including boost, rpm, temperature and more.
It also worked with my past 96 and 99 gas powered XJ's but I had to make a special cable for the 96 xj using just 3 lines on the obdii plug.
So anyone with a interface that will run the current version of the software go try it out. For those with older interfaces, if you still have your VW and a CRD use their update program and get a new one
I'm retired so I can get the answers for questions you might come up with
Joe