I own a 99 JGCL V8 4X4, 50000 miles. The Check Engine light went on and the transmission began to jerk from N to D and from 1st to
2nd gear. The code P0700 indicated transmission control module fault code. Replacing both transmission speed sensors fixed the problem. Actually the input sensor was bad. Part #4799061AB (same for both sensors), cost $27.50 (36.50 list) + 6.85 S/H from moparparts.com.
Thanks for all help, Les