stevenvdoss

Hello All,
And thanks for your time !
I have a 2005 E500 that has developed a cruise control issue that entails an inability to sustain a set speed. When I set the speed, say @ 70 mph, it will slow to 67-68, then resume the preset 70 mph. It repeats this process constantly throughout the time the cruise is engaged.
Does anyone have any ideas what may be causing this, and is it something someone with moderate mechanical skills could repair ?

vettdvr

Don't know why yours loses speed. It could be the speed sensor that sends the actual speed signal to the cruise and speedo. If you are driving stable w/o cruise does the speedo vary?

stevenvdoss

Thanks for your input. If the cruise is not on, there is no issue with maintaining speed. Does that change your thinking on the speed sensor ?

vettdvr

Just means it probably isn't the speed sensor. You probably need to check for codes to determine where the problem is.

Mine does funky stuff but the dealer has never found it. While driving using resume at times it will turn totally off. It will not come on or reset until I turn the engine off and restart. Then it comes back normal. Not a problem unless night driving then a pain.