cruise control not working sometimes

[flonly]

Ok where to start.Well I have had trouble with the cruise control not working right for as long as i can remember .Oh this is a 08 t660 kw.It will work then you will try to set it another time later and the screan will say that you need to press brake for it to work.when you do that then try to set it it will ony engage a second or not at all.It was working great for like 2 months then it got colder outside like mid 40's and back to same trouble.could there be a sensor outside the truck like on the transmission or something that cold weather is affecting?anyone have any trouble like this my right leg would appreciate the help

[hhow55]

I remember mine doing this,
When you turn on the ignition key, let the ecm system cycle before starting the engine.

[Waterloo]

If the ignition cycle like Howard stated does not work, disconnect the batteries for a few minutes. Make sure there is no power at all getting to the cab. My ProStar does goofy stuff like this on occasion and this is the typical fix. Mainly in the winter.

[flonly]

thanks guys I will try both to see if it fixes it

[Brock]

I have intermittent issues with mine, usually after coming to a complete stop then starting again. If mine won't engage, I just press the clutch in a tiny bit and release then the cruise will work. Seems my clutch pedal switch needs replacing or cleaning.....been like that for a long time and I've been fixing important stuff aND keep forgetting about it.

[gearhead]

Three things that normally will stop cruise and jakes. One the clutch pedal position switch either bad of week pedal return spring. second brake pedal sticking from the pin freezing up,dirt on the bottom under the pedal holding down slightly or the plunger in the foot valve freezing up from dirt or the pressure sensor on the service line from the brake pedal. Third the vehicle speed sensor signal.

[Rawze]

On some vehicles where those systems pass through the cab controller, I have seen instances where the cruise will also refuse to work if the panel fails the indicator lamp for it. Same thing for the jake brakes.

It will not be intermittent, but simply will not work at all.