This problem relates to an 03 XL with 41k miles.
The speedometer doesn't register the actual speed. It works when I accelerate but won't reset to zero when I stop (it sticks at approximately 20 MPH). When I start again, it takes off but has added 20 MPH to the speed. For example, I'll be actually going 35 MPH but the speedometer will read 55 MPH.
The problem is cumulative. When I stop again, it will add 40 MPH to the actual speed. It doesn't take too long and I'm doing 120 MPH while stopped at a light.
The only way to reset the speedometer is to repeatedly start and shut off the engine (It decreases the speed approximately 5 MPH with each cycle). Or, if I take the negative battery cable off and "arc" it across to the negative terminal.
My guess is that I have a grounding problem but I stink at automotive electrical issues. This happened once about 2 months ago and then reappeared this week and seems to be consistent.
Any thoughts from the list will be greatly appreciated.
Greg