OnStar Call Center Remote Function Requests Inoperative
OnStar Call Center Remote Function Requests Inoperative
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.
Circuit/System Description
The vehicle communication interface module (VCIM) is a 3-watt cellular device that allows the user to communicate data and voice signals over the national cellular network. It is powered by a fused battery positive voltage circuit, connected through the vehicle wiring to the inside rearview mirror containing the 3-button assembly and the radio. The VCIM receives its cellular signals by means of coax cables to the cellular and navigation antennas. Ground for the module is accomplished by means of dedicated circuits that are routed with body wiring systems to chassis ground points. The module houses 2 modems, one to process global positioning system (GPS) data, and the other for cellular information. Satellites orbiting earth are constantly transmitting signals of their current location, from which the OnStar(R) system is able to pinpoint its own location. The navigation antenna receives these GPS signals and provides the data to the VCIM to be processed. The VCIM communicates with the rest of the vehicle over the class 2 or GMLAN serial data bus, depending upon the serial data architecture of the vehicle. The ignition state is determined by the VCIM through class 2 or GMLAN messaging. The module also has the capability of commanding the horn, initiating door lock/unlock, and operating the exterior lamps using the serial data circuits. When an OnStar(R) keypress is made, a serial data message is sent to the audio system to mute all radio functions and transmit OnStar(R) originated audio. After the audio system is muted, the OnStar(R) signals are transmitted to the audio system on the left audio signal circuit (+) and the audio common signal circuit. The cellular modem connects the OnStar(R) system to the cellular carriers communication system by interacting with the national cellular infrastructure. The module sends and receives all cellular communications over the cellular antenna and cellular antenna coax.
Diagnostic Aids
The customer concern may have been due to a lack of cellular service in a given area. A failure in the National Cellular Network infrastructure that has since been corrected.
Reference Information
Schematic Reference
OnStar Schematics (OnStar Schematics)
Connector End View Reference
Component Connector End Views (Connector Views)
Description and Operation
OnStar Description and Operation (OnStar Description and Operation)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
Scan Tool Reference
Control Module References (Programming and Relearning) for scan tool information
Circuit/System Verification
Important: It is necessary to inform the OnStar(R) Call Center advisor that this call is for vehicle diagnostic purposes.
1. Verify that the horns, lighting systems, and the doors locks on the vehicle operate properly.
• If the applicable system does not operate properly, refer to Diagnostic Starting Point - Horns (Initial Inspection and Diagnostic Overview), Diagnostic Starting Point - Lighting (Initial Inspection and Diagnostic Overview), or Diagnostic Starting Point - Vehicle Access (Initial Inspection and Diagnostic Overview).
2. Contact the OnStar(R) Call Center by pressing the blue OnStar(R) button. Verify with the OnStar(R) advisor that all of the remote functions (door locks, lights, or horns) work.
• If the remote functions do not work, use the scan tool to access the STID and ESN and contact the General Motors Technical Assistance Center.