Just a general question about cruise control:

Unless I am traveling on a flat straight away, my cruise control fluctuates 5 mph up or down. Is this normal? Is there a way to fix it?

 

Its normal because the car doesnt use the brakes to slow itself down when its on cruise control it just uses the engine speed to try and slow it down... so yes it is very normal for it to vary around 5 MPH.

 

some of the earlier versions may have more play in them, but mine usually stays within 1-2mph of my set speed. it'll go over when I'm going uphill (too much gas), and it slows down as I'm going downhill.. basically it overcompensates.

If you're on steeper hills and have an automatic, it may compensate too much causing you to speed up to 5mph over the set speed when going over hills.

 

This 'feature' is a nuisance. The car has the pwr to keep the speed steady even on hilly ground, but it does not. If there was a way to do smtg...

 

sure.. revamp the entire cruise control system with different circuitry.

 

There is no schema I suppose. TOP Secret... I'd guess changing one resistor on the pcb would do the trick.