GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This is an internal Fault in the Vehicle Interface Module (VIU).

Conditions for Running the DTC

The VIU will run this internal test at the beginning of every wake-up cycle. Battery voltage is at least 9.5 volts and no more then 15.5 volts.

Conditions for Setting the DTC

VIU fails the EEPROM test.

Action Taken When the DTC Sets

The customer may complain of loss of OnStar® functionality since the VIU will use ROM as a default.

Conditions for Clearing the MIL/DTC

VIU successfully completes the EEPROM tests.

Diagnostic Aids

If B1009 sets intermittently, check that battery positive voltage and ground for poor connections.

Step

Action

Value(s)

Yes

No

1

Did you perform the OnStar® Diagnostic System Check?

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Go to Step 2

Go to OnStar System Check

2

Important: Perform the set up procedure for the VIU.

Replace the VIU. Refer to Vehicle Interface Unit and Vehicle Communication Unit Modules Replacement .

Did you complete the replacement?

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System OK

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