I’d look for a loose trans yoke nut first. If it’s loose, the VSS gets erratic signals from the pulse wheel while driving, and won’t set cruise.
While idling, the pulse wheel will vibrate and spin. In some instances, you can set high idle and it repeatedly kicks out, and in others it will never set.
After checking those, It’s much easier if you can hook up to the ECM with a Pro Link or laptop. There you could see every signal associated with cruise (clutch, park brake, service brake, switch status) and verify the ECM gets that signal when you operate that function.
Leave a Reply