Note: If Y91 is present on the RPO list, refer to
your owner's manual to adjust chimes.
1) With car on, shut off car and leave keys
in ignition. Open the car door and leave it
open. Chimes will be heard.
2) Wait 10 seconds, then with a small
screwdriver adjust the potentiometer
fully counterclockwise (all the way left),
then clockwise to raise chime level and
counterclockwise to lower the chime level.
3) When the volume is at the desired level,
remove the keys from the ignition. This will
lock the chime volume at its current level.
1) Start your vehicle and turn on the radio having audio playing.
2) Turn your aftermarket radio's volume up ¾ of the way.
3) With a small screwdriver adjust the potentiometer clockwise to raise the audio level and
counterclockwise to lower the audio level.
4) Once at desired level your audio adjustment is complete.
To adjust the OnStar volume level find the Black/Yellow wire on the 16-pin harness. Push
the blue OnStar button, while the voice is speaking tap the Black/Yellow wire to ground.
There are 4 volume settings for OnStar; once the 4th setting is reached and the Black/
Yellow wire is tapped to ground it will automatically go back to the first volume setting.
Once the volume is set it will stay at that volume until the Black/Yellow wire is tapped to
ground again. This can be set during installation and then left alone. If user adjustment is
desired, the customer may also tap volume up or down on the steering wheel (if equipped)
to adjust the OnStar level.
GMOS-09
Chime Volume Adjustment
Audio Level Adjustment
OnStar Level Adjustment
5
Potentiometer located on the 16 pin side
of the interface