OnStar Unwanted or Phantom Phone Calls - keywords call handsfree intermittent mmute OnStar OPC performance phantomcalls unwanted

This PI was superceded to update model years. Please discard PIC3278B

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

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

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

Hardware labeling:

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 6 = 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 1: The vehicle may receive an incoming call just like any other phone.

Scenario 2: This may involve a phantom call made to the OnStar® call center. The majority of these are due to the addition of the words "OnStar®" and "Emergency" to the voice recognition capability on early GEN 5 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 3: If the OnStar® call center makes an outbound data call to a vehicle with GEN 4 or 5 hardware, 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, GEN 6 and 7 do not ring into the vehicle when OnStar® connects for a data call). 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. All systems will ring into the vehicle when OnStar® places a voice call.

Scenario 4: 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 5: This may be seen on GEN 2 and GEN 3 systems 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 the VIU module and button assembly.

Scenario 6: Internal module fault. Some GEN 6 modules may exhibit a condition where "Phone Unavailable!" is heard repeatedly after the vehicle door is opened or key is cycled. The technician may find a DTC U1500 in the VCIM. Refer to PIC3718D for further information on this concern.

Scenario 7: Unwanted handsfree 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 may induce this event.

The majority of reported Phantom Phone Calls can be attributed to either a normal or customer induced concern. It is important to verify all aspects of the customer concern in order to duplicate the condition.

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.