The P0700 is a general code that indicates there is a problem within the trans control module. The 715 indicates a bad input speed sensor and the 720 is the output speed sensor. Since the speedo is at 30mph, I would suggest checking the output sensor and wiring to see if that is where the problem is coming from. Keep in mind, it could be the TCM itself.
Monday, September 14th, 2015 AT 6:17 PM