Test Description
The following procedure diagnoses the cause of the inoperative global position system (GPS) receiver. The following numbers refer to the steps in the table.
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This step ensures that OnStar® can communicate with the vehicle and that the OnStar® GPS system is configured.
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This step verifies proper operation of the GPS. The location that you are given from the OnStar® Center is only an approximate location. There can be variance in this location. Do not mistake location variance for a inoperative GPS system.
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It is necessary to have a good ground on the antenna to filter out signal noise.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the OnStar® Diagnostic System Check? | -- | Go to Step 2 | Go to OnStar System Check |
Did you complete the repair? | -- | Go to Step 2 | -- | |
Does the location given match your approximate location? | -- | Go to Step 10 | Go to Step 4 | |
4 | Is the GPS antenna installed in the proper location? | -- | Go to Step 5 | -- |
5 | Inspect the GPS antenna at the headliner. Is the grounding tab securely attached to the roof with the maximum area, as close as possible to the housing? | Go to Step 6 | Go to Step 4 | |
6 |
Is the antenna cable free from damage? | -- | Go to Step 7 | Go to Step 8 |
Test the ground circuit of the GPS antenna for a high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | -- | Go to Step 10 | Go to Step 9 | |
8 | Replace the GPS antenna. Refer to OnStar GPS Antenna Replacement . Is the repair complete? | -- | Go to Step 10 | -- |
9 | Replace the VIU. Refer to OnStar Vehicle Interface Unit Replacement . Is the action complete? | -- | Go to Step 10 | -- |
10 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 3 |
