Cruise Works Randomly

[Bigboytoys]

I got an 08 F250 4X4 6.4 auto and the cruise is not working very well.

There are times it won't turn on/set, other times it works great, then it will just shut off all on it's own.

Where do I start?

 

[sagebel]

Are you seeing any issues with your speedometer? Any codes? ABS light? Watch the speedo when you don't have CC. If it is, the issue may be the rear axle speed sensor.

 

[Bigboytoys]

Nope, I'm not getting any hard or soft codes, no CEL and the speedo doesn't drop off like it lost the signal.

 

[BIG JOE]

Nope, I'm not getting any hard or soft codes, no CEL and the speedo doesn't drop off like it lost the signal.

My vote would be the Speed Sensor. (VSS), on the rear Dif.

 

[Bigboytoys]

Ok I'll have to set up the scanner to graph the VSS on the next run to town.

 

[Tail_Gunner]

My brake pedal switch was very touchy. Just bump it and the cruise would disengage.

Try holding the brake pedal up with your foot and see if the situation changes. It may be a bad/misadjusted brake pedal switch.

 

[Bigboytoys]

Ya I tried that, it made no difference.

 

[95_stroker]

Look for a bad ground on one of your tail lights.

 

[Bigboytoys]

Ok that's not one of the first places I would have looked.....

 

[Bigboytoys]

Well after spending the afternoon chasing down every connection to and from the tail lights and cruise I still had a the same problem. The issue was fixed by.... opening up the actual cruise switch and cleaning the contacts of coffee or cola or what ever was in there. Easy to do but unhappiness abounded!