GM Service Manual Online
For 1990-2009 cars only

Important: Before attempting to diagnose the intrusion sensor, ensure that the intrusion sensor is ENABLED, via the intrusion sensor defeat switch.

Step

Action

Values

Yes

No

Schematic Reference: Theft Deterrent System Schematics

Connector End View Reference: Theft Deterrent System Connector End Views

DEFINITION: After arming, the Content Theft Deterrent (CTD) system does not enter alarm mode when there is motion inside the vehicle.

1

Did you perform the Diagnostic System Check - Vehicle?

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Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Turn OFF the ignition.
  2. Disconnect the intrusion sensor harness connector.
  3. Probe the intrusion sensor battery positive voltage circuit at the intrusion sensor harness connector with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

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Go to Step 3

Go to Step 7

3

With a DMM, measure the voltage of the intrusion sensor alarm on signal circuit at the intrusion sensor harness connector.

Is the voltage near the specified value?

B+

Go to Step 4

Go to Step 5

4

Test the intrusion sensor armed signal circuit for a short to ground, or an open. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

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Go to Step 11

Go to Step 6

5

Test the intrusion sensor alarm on signal circuit for an open or a short to ground. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

--

Go to Step 11

Go to Step 9

6

Inspect for a loose or poor connection at the harness connector of the intrusion sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

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Go to Step 11

Go to Step 8

7

Repair the intrusion sensor battery positive voltage circuit. Refer to Wiring Repairs .

Did you complete the repair?

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Go to Step 11

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8

Replace the intrusion sensor. Refer to Intrusion Sensor Inoperative .

Did you correct the condition?

--

Go to Step 11

Go to Step 9

9

Inspect for a loose or poor connection at the harness connector of the body control module (BCM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

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Go to Step 11

Go to Step 10

10

Replace the BCM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

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Go to Step 11

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11

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 2