Circuit Description
The navigation portion of the cellular and navigation antenna is connected to the vehicle communication interface module (VCIM) with an RG-174 coax cable. The VCIM polls the data from the 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 the cellular and 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 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
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 cellular and navigation antenna and the harness connector of the VCIM. 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 cellular and navigation antenna. Refer to Cellular and Navigation Antenna Assembly 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 in Computer/Integrating Systems for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
