Re: Cruise jerks
Welcome to the garage.
When you keep your foot on the accelerator, there is no surging?
The problem could be the TPS (throttle position sensor), but could eventually be the cruise control itself. You first need to be sure if the speedometer indication is smooth and without any flutter, because any prolem here could result in flutter of the cruise control. (the PCM receives the speed signal from the ABS system controller, sends it to the instrument cluster and uses it to control the cruise control).
Did you check if no DTC´s are stored in the PCM? To do so, you can do the key dance: ignition switch off/run three times and leave in run at the third time. Odometer should show DONE when no faults stored, or any fault code(s).