HUD and Analog Speedo don't match

[Dockery]

So first of all, let me say that yes I know search is my friend, but I can't seem to locate a thread on this (sometimes it all depends on what you keyword you search by). Sorry if this has been discussed already

However, my HUD and my Analog speedo don't match. The analog speedo is 3-5 mph slower. I have verified the HUD with an external Garmin GPS that shows the speed you are traveling.

My XLR has 20" tires on it, and are slightly larger than stock, but I would have thought they would still read the same. Is it possible that the HUD is fed from a different source than the Analog (like a GPS signal)?

Thanks in advance.

 

[ccclarke]

The HUD and IPC both get vehicle speed sensor info via the Class 2 bus. A tech 2 should isolate the cause pretty quick. Could be a bad gauge in the IPC.

CC