FreightLiner Classic Cruise Control

Discussion in 'Trucks [ Eighteen Wheelers ]' started by Firebird, Aug 12, 2009.

  1. Firebird

    Firebird Light Load Member

    Aug 13, 2006
    Bristol, VA
    Seems that there are some other people having cruise control problems, but none seem to be quite like mine, so.....

    '02 Freightliner Classic XL, Detroit 60. Turn the cruise on and set it and within a few seconds it kicks out...sometimes. Sometimes it will hold for 3 hours, then sometimes for 3 seconds.

    I pull bulk tankers so I use the PTO a lot. When I have the truck idled up to operate the blower, it will just kick the cruise out and the truck will return to idle.

    I have tried wiggling the brake and clutch pedals and the switches but cannot duplicate the problem.

    Any ideas?



    Oh yeah, it doesn't create any check engine codes, it just stops working.
  2. Heavyd

    Heavyd Road Train Member

    Feb 4, 2009
    Detroit cruise control/PTO modes work based on the signal from the Park brake switch. If you are cruising down the road and ECM sees the park brake has been applied, the cruise will cut out, same goes for when you are parked and have the engine RPM up in PTO mode the rpm will come back down to idle when the park brake is released again. Sounds like the park brake switch may be messing up. It is usually mounted in the yellow line from the dash park brake valves in behind the dash some where.
    kickin chicken Thanks this.

    CURTWAYNE Medium Load Member

    Jun 4, 2008
    I've asked this in the other threads as well, does your speedometer quit working as well?
    Safe Haul Thanks this.
  4. stranger

    stranger Road Train Member

    Oct 10, 2006
    I will tell you what my problem was in an IH I once had that did the same thing. The brake switch was bad. I am talking about the switch that kicks the cruise off when the brakes are applied.

    To be sure, I jumped across the terminals, and my problem went away. Now doing this will not let the cruise disengage when you hit the brake, so only do this as a diagonistic procedure that cost nothing.
  5. Les2

    Les2 Road Train Member

    Jul 25, 2008
    kicked back in my lazyboy...
    Isn't there also a breaker or sensor in the accelerator pedal that will cause this to happen?
  6. Firebird

    Firebird Light Load Member

    Aug 13, 2006
    Bristol, VA
    The brake switch has already been replaced.

    The speedometer is not affected when this happens. Nothing goes all weird or anything like that. It just stops working.

    I parked the other night and set the parking brake. We use air ride trailers so I very seldom set the trailer brakes to keep the air in the suspension.
    The truck would not idle up at all (best to idle it around 800 overnight. Just seems to smooth out a little and be a little easier on oil and fuel consumption). I tried several times during the night to idle it up. The next morning I pulled it over to the garage to let them see exactly what it was doing, but when I parked, it started working.

    That park brake switch sounds like a possibility. Any way I can bypass it or test it. Just for diagnostics of course on the bypass.

    Thanks for all the help.

  7. 2fuzy

    2fuzy Road Train Member

    Jun 19, 2008
    Granite Canon,WY
    do your jakes work?
  8. Firebird

    Firebird Light Load Member

    Aug 13, 2006
    Bristol, VA
    yep, the jakes and everything else in the truck works fine. The cruise just quits just like you reached over and turned it off.
  9. HISPEED428

    HISPEED428 Light Load Member

    Mar 28, 2009
    Plum Coulee,MB
    Does it happen even if you have all the lights off??? Had somethin similar happen on my Pete.Cruise worked fine all day and as soon as I turned on my lights at dusk it would kick out the cruise.Turns out the plug for my taillight/breaklight had come loose inside my stainless lightbox.Plugged it back in,problem solved.Hope that helps
  10. Firebird

    Firebird Light Load Member

    Aug 13, 2006
    Bristol, VA
    Lights on or off, doesn't matter. I have been looking for something that coincides with the cruise going out, but haven't had anything that happens every time that it quits.

    Thanks for all the suggestions,

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