Have an 05 Expy w/74,000 miles. We just made a trip have way across country and back, and the cruise control starting shutting it self off. At first it was after we used it for a while, then it started shutting off right after we set it. My father-in-law thinks it's just a vacuum leak that can be fixed pretty inexpensive. Has anyone else had this same problem? If so, what was the cause?

 

The 05 Expy doesn't use vacuum for the cruise (it's all electronic and is controlled by the PCM) so Dad's idea won't pan out.

Have the system scanned with a scan tool that is capable of reading "manufacturer-specific" codes as any speed control fault will be logged by the PCM, same as an emissions fault but without a visual fault indicator.

Common failures include the deactivator switch, the BPP switch, and the clockspring.

 

Thanks for the info, will have it checked out.

 

If the airbag light comes on too.It's more than likely the clockspring.

 

The airbag light doesn't come on.

 

is it turning the cruise off entirely, or just disengaging it?

if it's dis-engaging, as Project said, it's going to most likely point to one of the switches.

 

Those units had a Ford Recall I think (check with your dealer). Just ask your dealer if the cruise control recall work was done on your SUV.
Sounds as though you have a switch problem and I don't know if the switch is replaced under the recall or not. Seems as though a fuse is installed in the circuit on the recall.

 

No, the speed control recall did not affect the 05s.

 

We already checked the recall, it didn't affect the '05's as project said. It's turning it off completely.

 

I don't know how to check the clockspring, but to test if you are losing power to the system, check the yellow /lt blue striped wire coming off fuse 5 in the distribution block. It goes through the horn relay and comes out dark blue then goes into the clockspring.

Might be worth probing it and giving the connections a shake. Or, check fuse 5 (20a) who knows maybe it's loose, or the horn relay is starting to crap out.

Since it's turning off all togethor, I think you can rule out the brake pedal and speed sense switches, but could be wrong.

 

Thanks for all the suggestions. Will look into them when I get some free time.