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 is ON solid or always flashing.

1

Did you perform the Theft Deterrent Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Theft Deterrent

2

  1. Turn OFF the ignition.
  2. Disconnect the intelligent switching unit (ISU) PE3 connector.
  3. Turn ON the ignition, with the engine OFF.

Is the security indicator ON?

Go to Step 3

Go to Step 4

3

Repair the security indicator control circuit for a short to ground. Refer to Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 5

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4

Important:  Perform the program procedure for the ISU.

Replace the ISU. Refer to Intelligent Switching Unit Replacement in Body Control Systems.

Did you complete the replacement?

Go to Step 5

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5

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2