Circuit Description
The DTC B1000 is an internal microprocessor malfunction of the vehicle interface unit (VIU) and cannot be repaired. If the VIU power and ground circuits are operating normally and the B1000 code is current and cannot be cleared, then the VIU must be replaced .
Conditions for Running the DTC
The ignition must be in the Run or ACC position and the VIU power must be on. The VIU will run this internal test every 300 msec. Battery voltage must be at least 9.5 volts and no more that 15.5 volts.
Conditions for Setting the DTC
The VIU is unable to communicate with the GPS module for 10 seconds.
Action Taken When the DTC Sets
When the DTC is current, the VIU sees all information received from the global positioning system (GPS) module as Invalid.
Conditions for Clearing the DTC
The VIU is able to communicate with the GPS module.
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Did you perform the OnStar® Diagnostic System Check? | -- | Go to Step 2 | Go to OnStar System Check |
2 | Inspect for poor connections at the harness connector of the VIU module. 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 4 | Go to Step 3 |
3 | Replace the VIU module. Refer to OnStar Vehicle Interface Unit Replacement . Did you complete the replacement? | -- | Go to Step 4 | -- |
4 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
