GM Service Manual Online
For 1990-2009 cars only

OnStar Customer Reports (Phantom Phone Calls) Without Attemping A Call - keywords calling calls cellular free hands HFC intermittent mute OPC performance phantomcalls UE1

Subject:OnStar Customer reports (Phantom Phone Calls) without attempting a call

Models:1999-07 Buick Allure, Century, LaCrosse, LeSabre, Rainier, Rendezvous, Regal and Terraza
1999-07 Cadillac Escalade (All), CTS, Catera, Deville, DTS, SRX, Seville, STS and XLR
2003-07 Chevrolet Express Van
2002-07 Chevrolet Avalanche, Silverado, Suburban, Tahoe (all) , TrailBlazer ALL, Venture, and Uplander
2004-07 Chevrolet Colorado, Impala, Lumina, Cavalier, Monte Carlo, Corvette, Malibu, Maxx, Cobalt and Equinox
2002-07 GMC Arcadia, Envoy (All), Savana Van, Sierra, Canyon, Yukon and Yukon Denali
2003-07 Hummer H2, H3 and SUT
2001-04 Oldsmobile Aurora, Bravada and Silhouette
2000-07 Pontiac Aztec, Bonneville, Grand Prix, Sunfire, Montana, SV6, G5, G6, Vibe and Pursuit
2002-07 Saturn Aura, Ion, Sky, LS, Outlook, Relay and VUE



This PI was superseded to update model years. Please discard PIC3278A.


The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern:

An owner 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.

Below are the areas which we have found to contribute to this type of reported calls.

 

Generation 1 = Dealer installed handset system

 

Generation 2 = Three button kit/factory installed system - formally referred to as 2.0 system

 

Generation 3 = Three button factory installed system capable of OnStar Hands Free Calling (HFC) - formally referred to as 2.6 system

 

Generation 4 = Three button factory installed system capable of HFC and Memo Record - formally referred to as F1 system

 

Generation 5 = Three button factory installed system capable of HFC, Memo Record and Dual Tone Multi-funcition Tones (DTMF) - Analog system

 

Generation 6 = Three button factory installed system capable of HFC, Memo Record and DTMF - Digital/Analog system

 

Generation 7 = Three button factory installed system capable of HFC, Memo Record and DTMF - Digital/Analog system

 

Geo MIN = the phone number, geographically assigned, to each OnStar system

 

Scenario number one:

The vehicle/owner may be receiving calls (apparently HFC) at any time. When the customer attempts to answer there is no one there. In this case (with a Geo MIN) someone is actually dialing the phone number assigned to the OnStar system within the vehicle and hanging up when they hear someone answer the phone unexpectedly. A typical wrong number was dialed. Keep scenario number three below in mind also.

Scenario number two:

This may involve a phantom call made to the OnStar call center. We believe the majority of these are due to the addition of the words "OnStar" and "Emergency" to the voice recognition capability on Gen 5 and above systems. The customer may press the White dot button or the steering wheel control button and the system misinterprets a sound or the spoken word as either OnStar or emergency and places a call. This may be caused by either background noise or a cough etc. as well.

Scenario number three:

This third area has to do with the behavior of the Gen 4 and Gen 5 OnStar hardware. If the OnStar call center makes an outbound call to the car it will only ring once in the vehicle before the call is automatically answered by the hardware - called auto-answer (Gen 3 rings indefinitely or until a white dot button press). If the customer presses the white dot button the system will disconnect the OnStar advisor from the vehicle. In this scenario the call center would only be calling back if they were disconnected at some point in time.

Scenario number four:

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 number five (Gen 2 and 3 only):

An outbound call is being made and will likely not complete and result in modem tone screech or fast busy beeping. The button assembly LED may or may not flash. The operator will not be able to end call by pressing the Call Answer/Call End (DOT) button. "Connecting to OnStar" jingle is not heard. This condition may result in a dead battery. If "Connecting to OnStar" jingle is NOT heard, replace VCU with appropriate part. If jingle is heard, follow normal diagnostics checking for unintentional call initiation and integrity of circuits between OnStar VIU module and OnStar Button Assembly.

When attempting resolution it is very important to determine under which circumstances the reported Phantom Phone call resulted.

Recommendation/Instructions:

Most of these type calls have been found to be operator error and/or phone calls being incoming placed to the assigned phone number for the vehicle involved.

Some education and/or duplication of the concern may be required to further analyze and determine the type of calls the system is transmitting and/or receiving prior to any actual repair.

Repair/education as required after a thorough diagnosis.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.