GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: The interior courtesy lights do not turn ON for 40 seconds when the following conditions exist:

    • You use the door key cylinder in order to unlock one of the front doors or the rear liftgate door.
    • The interior lamps override switch is on (the interior courtesy lights are enabled).

1

Did you perform the Interior Lights System Check?

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Go to Step 2

Go to Interior Lamps System Check

2

Observe the service parts identification label for RPO UA6. Refer to Service Parts ID Label .

Is the vehicle equipped with the content theft deterrent (RPO UA6)?

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Go to Step 3

Go to Step 6

3

  1. Disconnect the inoperative key cylinder lock switch electrical connector.
  2. Use a test lamp in order to connect between B+ and the key cylinder lock switch harness connector terminal C.

Did the test lamp light?

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Go to Step 4

Go to Step 7

4

  1. Turn the ignition switch to the LOCK position.
  2. Disconnect the body control module (BCM) connector C2.
  3. Use a J 39200 digital multimeter (DMM) in order to measure the resistance between the key cylinder lock switch harness connector terminal D (terminal B when checking the liftgate lock) and the BCM harness connector C2 terminal C5.

Is the resistance within the specified range?

Less than 10 ohms

Go to Step 5

Go to Step 8

5

  1. Insert the key in the operative door cylinder lock.
  2. Rotate the key to the UNLOCK position.
  3. Complete one of the following tests:
  4. • Use a J 39200 DMM in order to measure the resistance between the key cylinder lock switch harness connector terminals C and D.
    • Use a J 39200 DMM in order to measure the resistance between the lift gate lock switch harness connector terminals B and C.

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 9

Go to Step 10

6

The door key unlock illumination feature is only available on vehicles equipped with the content theft deterrent (RPO UA6).

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7

Repair the following conditions in CKT 750:

    • A poor connection
    • An open

Is the repair complete?

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Go to Step 11

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8

Repair the following conditions in CKT 781:

    • A poor connection
    • An open

Is the repair complete?

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Go to Step 11

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9

  1. Inspect the BCM connector C2 terminal C5 for poor terminal contact.
  2. If the BCM connector C2 terminal C5 is OK, replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Is the repair complete?

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Go to Step 11

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10

Replace the key cylinder lock switch. Refer to Front Side Door Lock Replacement in Doors.

Is the repair complete?

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Go to Step 11

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11

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall the connectors/components that you removed.
  3. Turn the ignition switch to the RUN position for 6 seconds.
  4. Turn the ignition switch to the LOCK position.
  5. Remove the BCM PRGRM fuse.
  6. Turn the ignition switch to the ACC position.
  7. The BCM sounds the chime a number of times equivalent to the BCM type installed on the vehicle.

  8. Within 1 second, turn the ignition switch from the ACC position to the LOCK position, then back to the ACC position.
  9. The BCM sounds any DTCs stored.

Are there any BCM DTCs present?

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Go to Diagnostic System Check - Body Control System in Body Control System

Go to Interior Lamps System Check