I apologize if this has been covered,I have searched and didnt come up with the proper answer.When doing the bypass on the x940bt, does hooking up the vss wire negate the bypass mod? Thanks in advance, Steve.

to my knowledge, no, if you are using the hardware bypass and grounding KMODE pin (aka moving the mute wire on a/v harness)

I just finished installing my AVIC-X940BT in my 07 Hummer H3.

I grounded the KMODE pin by moving the MUTE wire up in the connector.

And, connected the VSS wire.

Everything seems to be working perfectly.