GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Buick 🢒 2005 🢒 Park Avenue 🢒 Vehicle Control Systems 🢒 Vehicle DTC Information 🢒 Courtesy Lamps Inoperative

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

Important:: The ambient light sensor must indicate low light conditions for the interior lamps to operate.

  1. Open and close all of the doors.
  2. Turn the courtesy lamp switch ON and OFF.
  3. Turn ON the ignition, with the engine OFF.

Do the courtesy lamps operate properly?

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3

Does the twilight sentinel operate properly?

Go to Step 4

Go to Twilight Sentinel Inoperative

4
  1. Install a scan tool.
  2. With a scan tool command the Theatre Dimming 1 output ON from the body control module (BCM) Output Control data list.
  3. Observe the following lamps:
    4. • Door courtesy lamp - LF
    • Door courtesy lamp - LR
    • Door courtesy lamp - RF
    • Door courtesy lamp - RR
    • I/P Courtesy Lamp - Right
  4. With a scan tool, command the Theatre Dimming 2 output ON from the BCM Output Control data list.
  5. Observe the following lamps:
    6. • Courtesy/reading lamp - LF
    • Courtesy/reading lamp - LR
    • Courtesy/reading lamp - RF
    • Courtesy/reading lamp - RR
    • I/P Courtesy Lamp - Left

Did all of the lamps turn ON?

Go to Step 6

Go to Step 5

5

Are all of the lamps inoperative?

Go to Step 10

Go to Step 11

6
  1. Position the courtesy lamp switch to the ON position.
  2. With a scan tool, observe the Courtesy Switch parameter in the body control module (BCM) Inputs data list.

Does the scan tool display ON?

Go to Step 7

Go to Step 8

7
  1. Open all the doors.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe all of the Dome/Buzzer Switch input parameters in the drivers door module (DDM) Inputs data list.

Does the scan tool display ON for all the Dome/Buzzer Sw. inputs?

Go to Step 21

Go to Step 9

8
  1. Disconnect the headlamp lamp switch.
  2. Connect a fused jumper between the courtesy lamp switch on signal circuit and the courtesy lamp switch ground circuit.
  3. With a scan tool observe the Courtesy Switch parameter in the BCM inputs data list.

Does the scan tool display ON?

Go to Step 20

Go to Step 12

9
  1. Turn OFF the ignition.
  2. Disconnect the inoperative door lock actuator.
  3. Connect a 3-amp fused jumper between the door lock actuator door latch switch signal circuit and the door lock actuator ground circuit of the inoperative door lock actuator.
  4. Turn ON the ignition, with the engine OFF.
  5. With a scan tool, observe the inoperative Dome/Buzzer Switch Input parameter.

Does the scan tool display ON for the inoperative Dome/Buzzer Sw. input?

Go to Step 18

Go to Step 14

10
  1. Turn ON the ignition, with the engine OFF.
  2. Position the courtesy lamp switch to the HI position.
  3. With a scan tool observe the Inadvert. Power Output status in the BCM Outputs data list.

Does the Inadvert. Power Output Status indicate ON?

Go to Step 16

Go to Step 21

11
  1. Turn ON the courtesy lamps.
  2. Remove the inoperative courtesy lamp bulb.
  3. Connect a test lamp between the courtesy lamp supply voltage circuit and the courtesy lamp low control circuit or the courtesy lamp control circuit of the inoperative courtesy lamp bulb.

Does the test lamp illuminate?

Go to Step 22

Go to Step 16

12

Test the courtesy lamp switch ground circuit for high resistance or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 13

13

Test the courtesy lamp switch on signal circuit for high resistance, open or short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 21

14

Test the inoperative door lock actuator ground circuit for an open or short to power. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 15

15

Test the inoperative door lock actuator door latch switch signal circuit for an open or high resistance. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 19

16

Test the courtesy lamps supply voltage circuit for high resistance, an open or a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 17

17

Test courtesy lamp low control circuit or courtesy lamp control circuit for an open or short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 21

18

Inspect for poor connections at the harness connector of the inoperative door lock actuator. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 23

19

Inspect for poor connections at the harness connector of the inoperative door control module. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 24

20

Inspect for poor connections at the harness connector of the headlamp switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 25

21

Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 26

22

Inspect for poor connections at the inoperative courtesy lamp bulb. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 28

Go to Step 27

23

Replace the inoperative door lock actuator. Refer to Front Side Door Latch Replacement or Rear Side Door Latch Replacement in Doors.

Did you complete the replacement?

Go to Step 28

--

24

Replace the door control module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 28

--

25

Replace headlamp switch. Refer to Headlamp Switch Replacement .

Did you complete the replacement?

Go to Step 28

--

26

Replace the BCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 28

--

27

Replace the inoperative courtesy lamp bulb.

Did you complete the replacement?

Go to Step 28

--

28

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2