During diagnostic testing of the OnStar® system, the technician should ensure the vehicle is
located in an area that has a clear unobstructed view of the open sky and preferably, an area
where analog cellular calls have been successfully placed. These areas can be found by
successfully making an OnStar® keypress in a known good OnStar® equipped vehicle and
confirming success with the OnStar® Call Center advisor. Such places can be used as a
permanent reference for future OnStar® testing.
OnStar® Personal Calling
The hands-free, OnStar® Personal Calling (OPC) cellular phone feature is an additional option to
the OnStar® system. This feature is already embedded within the vehicle communication
interface module (VCIM); however, it must be activated by an OnStar® advisor. This is done
most often during the initial OnStar® configuration, if the home location of the vehicle is in a
geographic area where OPC is available. In the event this feature is not enabled, customers may
connect to the OnStar® Call Center by pressing the blue OnStar® button and asking an advisor if
OPC is available in their area. Users of the Generation 6 OnStar® system can verify the system
has been configured for OPC by pressing the Answer/End Call button, waiting for the system to
respond "OnStar Ready" then speaking "dial". If the system responds "phone unavailable" the
system has not been configured for OPC. All other responses confirm that OPC has been enabled.
Operation of the Hands-Free Cellular Phone
OnStar® Personal Calling (OPC) operates similar to most hand-held cellular phones in that the
availability for its usage is based on minutes or units. The customer must have a current OnStar®
subscription, as this feature cannot be utilized without it. To use OPC, the customer must also
purchase units as outlined in the owner's guide provided with the OnStar® system. When the
customer purchases minutes, an OnStar® advisor loads these minutes into the vehicle
communication interface module (VCIM) over the airwaves at the time of the request or through
a discrete cellular call to the vehicle at a later time. Once loaded into the module, the units may
be used for non-international, outbound cellular phone calls and connection with the OnStar®
Virtual Advisor. Units begin to deplete (1 unit is equal to 1 minute) as the customer makes
outbound phone calls, answers inbound phone calls or while connected to the OnStar® Virtual
Advisor. In addition, units also have an expiration date, depending upon the type of units
purchased. This date is established when the download is performed and any remaining units
expire when the date within the VCIM, which is based on current date and time transmitted by
global positioning system (GPS) satellites, has passed. At any time, the user can press the
Answer/End Call button, say "Units" and verify the number of units remaining.
During a hands-free call, the microphone and audio system operate the same way as a standard
OnStar® call. When the Answer/End Call button is pressed, the audio system will mute; the
OnStar® system will then return the prompt "OnStar Ready". At this point there are specific
2007 Hummer H3
2007 ACCESSORIES AND EQUIPMENT Cellular, Entertainment and Navigation - H3