The cruise control on my truck keeps the speed but it is constantly accelerating and decelerating, more noticeable at slower speeds.
Any help on how I can diagnose/fix this issue will be greatly appreciated.
Felipe

 

Felipe,

My D2 does the same. I can feel it more than anything else and may notice a very small fluctuation in RPM but speed pretty much remains as set. Have never seen it on my other vehicles but I've assumed it was normal LR CC behavior?

Interested in seeing what other have to write.
......

 

Have you read the owners handbook?

The cruise shouldn't work below 40 mph but as soon as it reaches that speed it then speeds up and it returns to where you last set it.

 

It does it above 40 MPH!

 

Cruise in my 04 works perfectly.
Holds the speed it was set to.
Only gains 1-2 mph, if that, going down steep hills.

 

My '04 works exactly the same as Felipe's and Number9's. It makes the truck drive like my Mom. Super annoying. I've never had another vehicle's cc be so poor. I just never use it. It didn't occur to me it may be broken, I figured it was just a bad design.

 

As Number9 said, it's more of a feel thing. It's subtle enough (though not that subtle) where I could see some drivers not noticing it. But, it would be one of those things where once you notice it, there is no going back. I'm excited at the thought, where others have reported their's doesn't do it, that it may be fixable.

 

Adjust the CC/Throttle Cable slack. Rave has the exact specs, but I've had better results with having maybe 1-2mm between the CC/Throttle Cable & the throttle body plates. It will keep it from surging. If the gaps are uneven or large you'll feel it surge as it is taking up the slack.

 

This^

 

I've never bought a D2 that I didn't have to adjust the CC/Throttle Cable slack on. Heck two of em were SO bad that I adjusted them before I drove them home! It's amazing how it can easily make a sluggish LR feel peppy since you don't have loads slack in the throttle cable anymore!

I've also noticed from owning so many D2's that the 4.0L seems to activate the CC better or should I say more smoothly vs a 4.6L (when both are properly adjusted). I was told WAY back in the day that the 4.0L had different programming for the enable/disable of the CC in the ECU vs a 4.6L, but if the slack is adjusted out of the CC/Throttle Cable it should only surge for 1-5 seconds and then it should smooth out.

If the CC/Throttle body slack is bad hang on because it'll constantly surge. Also check your cables to make sure they're smooth with no kinks as that can also cause it to surge.