New m9 phone not connecting to headunit.8100 updated firmware .plugged into USB2.also bypassed video. .getting red screen on phone.stating apply parking brake.reinstalled AA on phone.still get a red screen..please help..

You don't have the PB wire connected to ground, do you?

No .it's not grounded..

does it have to be?

Thank you NYC ..I grounded the PB wire.it now works

great