My d3 with xm unit gex-p920xm will not retain xm presets and when car is turned off xm restarts and channel 001 reguardless of what channel was on. radio presets are retained. bluetooth connection and phone book retained. nav home retained. whats wrong?

Make sure the xm tuner isn't losing power when the vehicle is off.

Did you tap into constant, or accessory?

I had the same problem you have to connect the yellow wire to constant 12v

Just go yellow to yellow on AVIC harness.. Easy enough.