GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

The courtesy lights do not turn on when a passenger door is open. The courtesy light turn on when the IP dimmer switch is in the DOME switch.

1

Was the Interior Lights System Check performed?

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Go to Step 2

Refer to Interior Lamps System Check

2

Did you perform the BCM Diagnostic System Check?

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Go to Step 3

Refer to Diagnostic System Check - Body Control System

3

  1. Turn the ignition switch to the LOCK position.
  2. Connect the Tech 2 scan tool to the Data Link Connector (DLC).
  3. Turn the ignition switch to the RUN position.
  4. Use the Tech 2 scan tool in order to monitor the status of the DRI DOOR SW.
  5. While observing the Tech 2 scan tool, open then close the driver's door.

Does the Tech  2 scan tool display that the status of the DRI DOOR SW is low when the driver's door is open?

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Go to Step 4

Go to Step 5

4

  1. Ensure that all the vehicle doors are closed.
  2. While observing the Tech 2 scan tool, open then close each vehicle door, one door at a time.

Does the Tech 2 scan tool display that the status of the DOOR JAMB SW is low when each vehicle door is open?

--

Go to Step 6

Go to Step 7

5

  1. Leave the driver's door open.
  2. Use a DMM in order to probe and measure the resistance between the following components:
  3. • The Body Control Module (BCM) connector C1 terminal D16
    • Ground

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 9

Go to Step 10

6

  1. Disconnect the Tech 2 scan tool from the DLC.
  2. Ensure that all the vehicle doors are closed.
  3. Turn the ignition switch to the RUN position.
  4. While observing the courtesy lights, open then close each vehicle door, one door at a time.

Do courtesy lights turn on when each vehicle door is open?

--

Go to Step 8

Go to Step 9

7

  1. Open an inoperative door. Note: If none of the doors turns on the courtesy lights, then leave the driver's door open.
  2. Use a DMM in order to backprobe and measure the resistance between the following components:
  3. • The Body Control Module (BCM) connector C1 terminal C16
    • Ground

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 9

Go to Step 11

8

A malfunction is not present at this time. Refer to Interior Lights Circuit Description for more information regarding the operation of the courtesy lights.

Has the repair been made?

--

Go to Step 18

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9

  1. Inspect the BCM connector for a poor terminal contact. Perform repairs as necessary.
  2. If the BCM connector is OK, then replace the BCM. Refer to Body Control Module Replacement in Body Control System.
  3. After BCM replacement, perform Setup New BCM Procedure. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Has the repair been made?

--

Go to Step 18

--

10

  1. Disconnect the driver's door lock switch electrical connector C1.
  2. Use a test light in order to connect the following components:
  3. • B+
    • The door lock switch harness connector C1 terminal D

Does the test light illuminate?

--

Go to Step 12

Go to Step 13

11

  1. Disconnect the inoperative door lock switch electrical connector C1.
  2. Use a test light in order to connect between B+ and the following components:
  3. • Left front or left rear door lock switch harness connector C1 terminal D
    • Right front or right rear door lock switch harness connector C1 terminal A

Does the test light illuminate?

--

Go to Step 14

Go to Step 13

12

  1. Disconnect the BCM connector C1.
  2. Use a DMM in order to measure the resistance between the following components:
  3. • The BCM harness connector C1 terminal D16
    • The driver's door lock switch harness connector C1 terminal C

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 15

Go to Step 16

13

Repair a poor connection or an open in circuit 750.

Has the repair been made?

--

Go to Step 18

--

14

  1. Disconnect the BCM connector C1.
  2. Use a DMM in order to measure the resistance between the BCM harness connector C1 terminal C16 and the following components:
  3. • Left front or left rear door lock switch harness connector C1 terminal B
    • Right front or right rear door lock switch harness connector C1 terminal C

Is the resistance within the specified range?

Less than 2 ohms

Go to Step 15

Go to Step 17

15

Replace the inoperative door lock switch assembly.

Has the repair been made?

--

Go to Step 18

--

16

Repair a poor connection or an open in circuit 49.

Has the repair been made?

--

Go to Step 18

--

17

Repair a poor connection or an open in circuit 727.

Has the repair been made?

--

Go to Step 18

--

18

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall any removed connectors or components.

Have all the repairs been made?

--

Refer to Interior Lamps System Check

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