GM Service Manual Online
For 1990-2009 cars only

System Description

This vehicle uses a unique method of performing the door unlock feature when requested by the customer, to be performed by the OnStar® Call Center. A dedicated circuit from the vehicle communication interface module to the driver door lock switch unlock signal circuit at the body control module (BCM) is used for operating the remote door unlock feature.

Diagnostic Aids

The customer concern may have been due to a lack of cellular service in a given area or a failure in the National Cellular Network infrastructure that has since been corrected.

Step

Action

Yes

No

Schematic Reference: OnStar Schematics

Connector End View Reference: Cellular Communication Connector End Views

1

Did you perform the Cellular Communication Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Cellular Communication

2

Operate the door locks by using either the driver or passenger door lock switch.

Do the door locks operate properly?

Go to Step 3

Go to Diagnostic System Check - Door Systems in Doors

3

Important: It is important to have the vehicle in an open outside area where a cellular call can be successfully placed and Global Positioning System (GPS) data can be received from satellites. It is also necessary to inform the OnStar® Call Center advisor that this call is for vehicle diagnostic purposes.

  1. While inside the vehicle, lock and close the vehicle doors.
  2. Press the OnStar® Call Center button.

Is a connection made with the OnStar® Call Center?

Go to Step 4

Go to Unable to Contact OnStar Call Center

4

Ask the OnStar® Call Center advisor if this call was a fail to voice.

Was this call a fail to voice?

Contact the General Motors Technical Assistance Center

Go to Step 5

5

Ask the advisor to perform a door unlock request.

Is the door unlock request successful?

Go to Diagnostic Aids

Go to Step 6

6

Inspect the driver door lock switch unlock signal circuit for an open or short to voltage.

Did you find and correct the condition?

Go to Step 7

Use the scan tool to access the STID and ESN, and contact the General Motors Technical Assistance Center

7

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2