PattyM, I have a manual that my rv came with but it doesn't really say anything other than how to use the volume buttons. There aren't any secret combination of pushes that does anything special. The manual is a very vague set of user button location instructions.
What are you trying to do?
If Bluetooth, first go to the find Bluetooth device on your phone and then hit the Bluetooth button on IRV66, your phone will find it. Select it and your paired. I don't think it asks for a passcode but if it does it will prompt off the stereo.
You trying to adjust bass, treble, etc? Just push the volume button in and it will toggle thru each option.
2015 Palomino Puma Unleashed 351-THSS 37' Toyhauler
2013 F-250 Lariat CCSB FX4 Kodiak Brown Metallic w/18k Superglide hitch and Air Lift rear air ride
"Just put that hammer down and give it hell" -Jerry Reed