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.

OnStar Call Center Remote Function Requests Inoperative

Step	Action	Yes	No
Schematic Reference: OnStar Schematics Connector End View Reference: Cellular Communication Connector End Views
1	Did you perform the Diagnostic System Check - Vehicle?	Go to Step 2	Go to Diagnostic System Check - Vehicle in Vehicle DTC Information
2	Attempt to honk the horn, operate the lights, and lock or unlock the doors on the vehicle. Does the applicable system operate properly?	Go to Step 3	Go to Diagnostic Starting Point - Horns in Horns Go to Diagnostic Starting Point - Lighting Systems in Lighting Systems Go to Diagnostic Starting Point - Doors in Doors
3	IMPORTANT: It is necessary to inform the OnStar® Call Center advisor that this call is for vehicle diagnostic purposes. Contact the OnStar® Call Center by pressing the blue OnStar® button. Ask the OnStar® advisor to perform a remote function (door lock/unlock, light flash, or horn honk). Was the attempt successful?	Go to Diagnostic Aids	Use the scan tool to access the STID and ESN and contact the General Motors Technical Assistance Center

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Diagnostic Aids

Use the Manual With the Right Hardware

When to See a Mechanic

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