GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Vehicle Theft Deterrent (VTD) System check?

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Go to Step 2

Go to Vehicle Theft Deterrent (VTD) System Check

2

  1. Listen to and feel the THFT 1 AND THFT 2 relays in the underhood fuse block.
  2. Cycle the ignition from RUN to START several times.

Do the relays actuate?

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Go to Vehicle Theft Deterrent (VTD) System Check

Go to Step 3

3

Has the vehicle theft deterrent (VTD) module been replaced?

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Go to Step 5

Go to Step 4

4

Replace the VTD module. Refer to Theft Deterrent Module Replacement .

Is the repair complete?

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Go to Vehicle Theft Deterrent (VTD) System Check

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5

Replace the powertrain control module (PCM).

Refer to Powertrain Control Module Replacement in Engine Controls-4.0L, 4.6L.

Is the repair complete?

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Go to Vehicle Theft Deterrent (VTD) System Check

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