GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Theft Deterrent System Schematics

Connector End View Reference: Theft Deterrent System Connector End Views

DEFINITION: The status of the security indicator never changes and the security indicator the security indicator never illuminates.

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Replace the theft deterrent control module. Refer to Theft Deterrent Module Replacement .

Did you complete the replacement?

Go to Step 4

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3

Important:  Perform the program procedure for the intelligent switching unit (ISU).

Replace the ISU.

Did you complete the replacement?

Go to Step 4

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4

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3