Cruise Control Disengaging

[gmenor]

Had this happen three times within the last 6 months where my cruise control disenages going through somewhat hilly terrain. Cruise control will not re-engage unless I shut down the engine to reset it. It seems to disengage underload going up a hill. This happened twice prior to having changing FSD out and once with the new one in. Didn't notice anthing different on boost or pyrometer reading. I'm in Alaska and flying back tonight to NC - Anchorage is definitely Cummins and Powerstroke country. Any thoughts?

[rjwest]

You do not state if you have any mods.

I had a Turbo master installed, when I had a down shift it would spike the boost and set defuel mode.
Do not recall if cruise was affected.

Note: there are " hidden " codes that will not set Mil light but affect a lot of things in the PCM.

These hidden codes can be reset by turning off ign.

[joed]

My 98 truck has done this since new, but only when towing and the speed drops considerably lower than the original cruise set point. It seems like the cruise circuit gets in a loop and kicks out of it.

I can always reset it though, without shutting the engine, so you may have a different issue.

Joe.

[JohnC]

Get a scanner and look at fuel solenoid closure time. My guess is that at higher power settings it starts to hang up.

[vernj4]

Same problem here. Once cruise control disengages, can hear a click in the radio when pressing the set button or the reset switch. The only solution is to turn off engine and restart. Then it works again for 2-3 times of braking and resetting

[eracers999]

Hook up a scanner, ill bet you will find trans slip or converter slip.

Kent

[gmenor]

Thanks for the help. I'll see if I can find someone other than the dealership to do it.

[phajna]

I had a similar problem on my '99 Suburban. The cruise finally stopped working. The engine computer ended up being faulty - replaced under warranty.