GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Saturn 🢒 2008 🢒 Astra 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 OnStar Call Center Remote Function Requests Inoperative

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

Circuit/System Description

The vehicle communication interface module (VCIM) has the capability of commanding the horn and initiating door lock/unlock. These functions are commanded by the OnStar® Call Center per a customer request.

Diagnostic Aids

The customer concern may have been due to a lack of cellular service in a given area.

Reference Information

Schematic Reference

OnStar Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

OnStar Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Circuit/System Verification

Important: 

   • When contacting the OnStar Call Center, explain to the OnStar advisor that this call is for vehicle diagnostic purposes.
   • It is necessary to have the vehicle in an open outside area where a cellular call can be successfully placed and GPS data can be received from satellites.

  1. Verify that the horn, lights, and the doors locks on the vehicle operate properly.
    2. ⇒If the applicable system does not operate properly, refer to Diagnostic System Check - Vehicle.
  2. Contact the OnStar® Call Center by pressing the blue OnStar® button. Verify with the OnStar® advisor that all of the remote functions (door locks and horn)work.
    3. ⇒If unable to connect with the OnStar® call center, refer to Unable to Contact OnStar Call Center.
    ⇒If the door locks do not operate when requested, refer to Remote Door Locks Malfunction.
  3. If the horn does not operate when requested, refer to Remote Horn Malfunction.

Circuit/System Testing

Remote Door Locks Malfunction

  1. Ignition OFF, disconnect the harness connector at the OnStar interface module.
  2. Ignition ON, test for less than 1 volt between the signal circuit terminal 3 and ground.
    3. ⇒If greater than the specified range, test the signal circuit for a short to voltage.
  3. Test for infinite resistance between the signal circuit terminal 3 and ground.
    4. ⇒If not the specified value, test the signal circuit for a short to ground.
  4. If all circuits test normal, replace the OnStar interface module.

Remote Horn Malfunction

  1. Ignition OFF, disconnect the harness connector at the OnStar interface module.
  2. Ignition ON, test for less than 1 volt between the signal circuit terminal 4 and ground.
    3. ⇒If greater than the specified range, test the signal circuit for a short to voltage.
  3. Test for infinite resistance between the signal circuit terminal 4 and ground.
    4. ⇒If not the specified value, test the signal circuit for a short to ground.
  4. If all circuits test normal, replace the OnStar interface module.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for OnStar integration module replacement, setup, and programming