GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This is an internal Microprocessor Malfunction of the Vehicle Interface Module (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 ms. 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 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.

  1. Determines that all connections are good for the VIU harness.

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 Vehicle Interface Unit and Vehicle Communication Unit Modules Replacement .

Did you complete the replacement?

--

Go to Step 4

--

4

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK