I don't have the answer.
But, far as troubleshooting goes, I'd want to start with the all connectors leading to/from the cruise module (including power and
ground connections. And, if they were all satisfactory and cleaned if necessary, and if that had no change, then I'd want to see if reinstalling the stock speedo calibration (chip) would solve the pulsing. And, do you have a the ability to do a scan to see what else is going.
Ultimately, you might want to swap out the cruise module for another module, if possible. And, if that results in fixing the problem, you have our answer and maybe BATEE (?) might be able to fix it (unless you are electronically inclined yourself!)
