GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2001 🢒 GMC C Sierra - 2WD 🢒 Body and Accessories 🢒 Cellular Communication 🢒 DTC B2462

Circuit Description

The GPS antenna is connected to the Vehicle Interface Unit (VIU) with a RG-174 coax cable. The VIU polls the data from the GPS antenna every 2.5 seconds.

Conditions for Running the DTC
    • The ignition must be in the RUN or ACC position.
    •  The system voltage is at least 9.5 volts and no more than 15.5 volts.
    • All the above conditions are present for greater than 2.5 seconds.

Conditions for Setting the DTC
    • The VIU does not detect a GPS signal.
    • All the above conditions are present for greater than 2.5 seconds.

Action Taken When the DTC Sets
    • The OnStar® status LED turns RED.
    • The OnStar® Call Center cannot locate the vehicle.

Conditions for Clearing the DTC
    • The VIU detects the presence of a GPS antenna.
    • A history DTC clears after 50 malfunction free ignition cycles.
    • The VIU receives the clear DTC command from the scan tool.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests for proper ground on the GPS antenna.

    2.

  2. This step tests the condition of the GPS antenna.

Step

Action

Yes

No

 

Schematic Reference: OnStar Schematics

 

1

Did you perform the OnStar® Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Cellular Communication

 

2

Inspect the GPS antenna for damage.

Is the antenna cable damaged?

Go to Step 4

Go to Step 3

 

3

Important:: The GPS antenna and the coaxial cable grounding tab must be mounted to the metal roof with the maximum contact area.

Test the GPS antenna coax cable ground for an open or high resistance. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 5

 

4

Replace the GPS antenna. Refer to OnStar GPS Antenna Replacement .

Is the repair complete?

Go to Step 7

--

 

5

Inspect for poor connections at the harness connector of the VIU. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 7

Go to Step 6

 

6

Replace the VIU module. Refer to OnStar Vehicle Interface Unit Replacement .

Did you complete the replacement?

Go to Step 7

--

 

7
  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK