Circuit Description
This vehicle will be equipped with either a stand alone navigation antenna or a combination cellular and navigation antenna. The navigation antenna is connected to the VIU with a RG-174 coax cable. The VIU polls the data from the 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 navigation 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 navigation 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.
-
This step tests for proper ground on the navigation antenna.
-
This step tests the condition of the navigation antenna.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: OnStar Schematics | |||
1 | Did you perform the OnStar® Diagnostic System Check? | Go to Step 2 | |
Inspect the navigation or cellular navigation antenna for damage. Is the antenna cable damaged? | Go to Step 4 | Go to Step 3 | |
|
Important: The navigation antenna and the coaxial cable grounding tab must be mounted to the metal roof with the maximum contact area. Test the navigation antenna coax cable ground for an open or high resistance. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 7 | Go to Step 5 | |
4 | Replace the navigation or cellular and navigation antenna. Refer to Navigation Antenna Replacement or Cellular and Navigation Antenna Assembly 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 to 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 |
Does the DTC reset? | Go to Step 2 | System OK |
