P0700 means there is a code in the TCM ( transmission control module ). P0605 means you have an internal tcm code for ROM, computer term ( read only memory ). According to my pdf files, the fix is to replace the tcm. But I have been able to reflash the controllers thru DCX aka chrysler, I would try a flash first before replacing the controller.
I spoke with my local Dodge dealership and they're not real happy about flashing the TCM. In fact the tech didn't even speak to me he just walked off, I had to speak with the supervisor. Even he was short, all he said was we'll flash the TCM for $90 and that's it.
....after speaking to a different service manager about flashing the TCM on the Caravan. They offered to do a diagnostic service, which was $20 dollars cheaper and included a TCM flash.
Unfortunately, the flash didn't work on the transmission, so it looks as though I'll have to replace the unit and have it flashed again......but, now I know.
Anyone have a good resource for TCM modules? $550 is a little steep from the dealer to replace the module.