Circuit Description
The navigation antenna is connected to the vehicle communication interface module (VCIM) with a RG-174 coax cable. The VCIM polls the data from the navigation antenna once every second.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B2483 GPS Sensor Circuit Low |
| • | DTC B2484 GPS Sensor Circuit Open |
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 1 second. |
Conditions for Setting the DTC
| • | The VCIM does not detect a navigation signal. |
| • | All the above conditions are present for greater than 1 second. |
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 VCIM detects the presence of a navigation antenna. |
| • | A history DTC clears after 50 malfunction-free ignition cycles. |
| • | The VCIM receives the clear DTC command from the scan tool. |
Step | Action | Values | 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 | |
2 |
Notice: Using a DMM to measure the resistance of the navigation antenna coax from the center conductor to the outer shield while the antenna is still connected will damage the navigation antenna. Important: Vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length of coax.
Does the meter read out of limits? | -- | Go to Step 3 | Go to Step 4 |
3 | Measure the resistance of the navigation antenna coax center conductor from end to end. Does the resistance measure greater than the specified value? | 1 ohms | Go to Step 4 | Go to Step 5 |
4 | Replace the navigation antenna coax. Did you complete the replacement? | -- | Go to Step 7 | -- |
5 | Inspect for poor connections at the navigation antenna and the harness connector of the VCIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition? | -- | Go to Step 7 | Go to Step 6 |
6 | Replace the navigation antenna. Refer to Cellular Communications/Digital Radio Antenna Replacement . Is the repair complete? | -- | Go to Step 7 | -- |
7 |
Does the DTC reset? | -- | Go to Step 8 | System OK |
8 | Replace the VCIM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | -- |
