Can't connect to car stereo after GDR2/Amber update

[Stephen Vogel]

My partner connects her Lumia 820 to her car stereo with a cable from the headphone jack on the phone to the AUX input on the car stereo. This has always worked perfectly for Xbox music pass, her own music on the phone etc.
After the GDR2 update the volume goes down to zero on the phone as soon as it connects to the car stereo. You can see the volume numbers on the phone roll right down to zero as soon as the cable is connected to the headphone jack and it is impossible to increase the volume.
Any suggestions? I am thinking it might have something to do with FM radio being activated after the update?
Any help would be appreciated

 

[stmav]

Does it do this when headphones are plugged in? Or just when using the headphone jack with the aux input?

 

[Stephen Vogel]

Does it do this when headphones are plugged in? Or just when using the headphone jack with the aux input?

Just with aux, headphones work fine