PIC3278G

Bulletin No.: PIC3278G
Published date: 02/20/2017
Preliminary Information
PIC3278G OnStar- Unwanted Or Phantom Phone Calls
Models
Brand:
All
Model:
All
VIN:
Model Years:
2000 - 2017
from
All
Engine:
to
All
All
Transmissions:
All
Supersession Statement
This PI was superseded to update Model Years. Please discard PIC3278E.
Condition / Concern
A customer may report that the OnStar® system is attempting and/or completing phone calls which the operator of the vehicle did
not initiate.
It is important to know which type of reported phantom phone call the operator is reporting. Some phone calls of this nature are
considered normal and cannot be addressed other than through education, while others may require some remedial action to
resolve. When attempting resolve, it is very important to determine under which circumstances the reported Phantom Phone call
resulted. Below is a list of generation hardware capabilities along with 4 different scenarios in which we have found to contribute
to these types of concerns.
Hardware labeling:
Generation 6 - Three button factory installed system capable of HFC, Memo Record and DTMF
Generation 7 - Three button factory installed system capable of HFC, Memo Record, Turn By Turn Navigation and DTMF
Generation 8, 9, 10 - Three button factory installed system capable of HFC, Memo Record, Turn By Turn Navigation, Bluetooth and
DTMF
Scenario 1:
The vehicle may receive an incoming call just like any other phone. Typically the customer will hear the phone ringing in the
vehicle. This scenario also includes incoming Bluetooth calls.
Scenario 2:
Because the button assembly and associated wiring feeds voltage back to the OnStar® system based on the amount of voltage
drop through each of the buttons, should the return line be partially shorted to voltage the system could interpret this voltage as a
key press. If one of the buttons voltage is simulated, such as the Blue button. The system will make a phone call just as if the button
had been pressed by the operator of the vehicle.
Scenario 3:
Internal module fault. Some customers may report a condition where ″Phone Unavailable″ message is heard after the vehicle door
is opened or key is cycled. The technician may find a DTC stored in the VCIM (example: U1500 or B1000). Refer to diagnostics for the
DTC making sure to follow any applicable Bulletins or PIs.
Scenario 4:
Unwanted Hands free calling activation. A customer may report that the ″Ready!″ or ″OnStar® Ready!″ message is heard while
driving. The customer may also advise that this seems to happen mostly while making a turn. In some cases it has been found that
the customer is inadvertently pressing the ″push to talk″ button on the steering wheel controls. On rare occasions, other issues in
the steering column or Steering Wheel Control system may induce this event.
Recommendations / Instructions
The majority of reported Phantom Phone Calls can be attributed to accidental button presses or customer induced concern. In
some cases an incoming call may be mistaken as a phantom call concern. It is important to verify all aspects of the customer
concern in order to duplicate and diagnose the condition.
Customer Information
If the concern points to normal operation and customer induced concern, please communicate to the customer this condition is a
normal operating characteristic of their vehicle. It will not impact the designed performance or reliability of the vehicle. Please
share this information with the customer, including a copy of this message.
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