GM Service Manual Online
For 1990-2009 cars only

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Schematic Reference: Interior Lights Schematics

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

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Important:: The sun load sensor assembly must indicate low light conditions for the courtesy lamps to operate.

  1. Cover the sun load sensor assembly.
  2. Observe the courtesy lamps.
  3. Open and Close all of the doors.
  4. Position the interior lamp switch to the ON, DOOR and OFF positions.
  5. Turn ON the ignition, with the engine OFF.
  6. Turn OFF the ignition.

Do the courtesy lamps operate properly?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool command the Courtesy Lamp 1, 2 w/o dim output ON from the rear integration module (RIM) Output Control data list.

Do all of the courtesy lamps turn ON?

Go to Step 5

Go to Step 4

4

Are all of the courtesy lamps inoperative?

Go to Step 11

Go to Step 15

5

  1. Position the interior lamp switch to the DOOR position.
  2. With a scan tool, observe the Interior Lamp Switch parameter in the IPM Non - HVAC data list.

Does the scan tool display DOOR?

Go to Step 6

Go to Step 8

6

  1. Position the interior lamp switch to the ON position.
  2. With a scan tool, observe the Interior Lamp Switch parameter.

Does the scan tool display ON?

Go to Step 7

Go to Step 9

7

  1. Open all the doors.
  2. Turn ON the ignition, with the engine OFF.
  3. With a scan tool, observe all the Door Jamb Sw. input parameters in the drivers door module (DDM) Inputs data list.

Does the scan tool display ON for all the door jamb Sw. inputs?

Go to Step 29

Go to Step 10

8

  1. Disconnect the interior lamp switch.
  2. Connect a 3-amp fused jumper between the courtesy lamps switch lamp off signal circuit and the interior lamp switch ground circuit.
  3. With a scan tool observe the Interior Lamp Switch parameter.

Does the scan tool display DOOR?

Go to Step 27

Go to Step 16

9

  1. Disconnect the interior lamp switch.
  2. Connect a 3-amp fused jumper between the courtesy lamps switch on signal circuit and the interior lamp switch ground circuit.
  3. With a scan tool observe the Interior Lamp Switch parameter.

Does the scan tool display ON?

Go to Step 27

Go to Step 17

10

  1. Turn OFF the ignition.
  2. Disconnect the inoperative door lock actuator.
  3. Connect a 3-amp fused jumper between the door open switch signal circuit and the 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 Door Jamb Sw. input parameter.

Does the scan tool display ON for the inoperative door jamb Sw. input?

Go to Step 25

Go to Step 19

11

  1. Turn OFF the ignition.
  2. Disconnect the INT LP relay.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the INT LP relay control side supply voltage circuit with a test lamp that connected to a good ground.

Does the test lamp illuminate?

Go to Step 12

Go to Step 32

12

Probe the INT LP relay switch side supply voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 13

Go to Step 31

13

  1. Connect a test lamp between the INT LP relay control side supply voltage circuit and the interior lamp relay control circuit.
  2. With a scan tool command the Courtesy Lamp 1, 2 w/o dim output ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step 14

Go to Step 23

14

  1. Connect a 10-amp fused jumper between the INT LP relay switch side supply voltage circuit and the courtesy lamp supply voltage circuit.
  2. With a scan tool, command the Courtesy Lamp 1, 2 w/o dim ON.

Do the courtesy lamps illuminate?

Go to Step 24

Go to Step 21

15

  1. Remove the inoperative courtesy lamp bulbs.
  2. Connect a test lamp between the inoperative courtesy lamp supply voltage circuit and the ground circuit of the inoperative courtesy lamp.
  3. Turn ON the courtesy lamps.

Does the test lamp illuminate?

Go to Step 30

Go to Step 21

16

Test the courtesy lamps switch lamp off signal circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 40

Go to Step 18

17

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

Did you find and correct the condition?

Go to Step 40

Go to Step 18

18

Test the interior 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 40

Go to Step 28

19

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

Did you find and correct the condition?

Go to Step 40

Go to Step 20

20

Test the inoperative door open 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 40

Go to Step 26

21

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

Did you find and correct the condition?

Go to Step 40

Go to Step 22

22

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

Did you find and correct the condition?

Go to Step 40

Go to Step 29

23

Test the control circuit of the INT LP relay for high resistance, an open or a short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 40

Go to Step 29

24

Inspect for poor connections at the INT LP relay. 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 40

Go to Step 33

25

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 40

Go to Step 34

26

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 40

Go to Step 35

27

Inspect for poor connections at the harness connector of the interior lamp 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 40

Go to Step 36

28

Inspect for poor connections at the harness connector of the IPM. 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 40

Go to Step 37

29

Inspect for poor connections at the harness connector of the rear integration module (RIM). 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 40

Go to Step 38

30

Inspect for poor connections at the inoperative courtesy lamp bulb connector. 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 40

Go to Step 39

31

Repair the open or high resistance in the switch side supply voltage circuit of the interior lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 40

--

32

Repair the high resistance or open in the control side supply voltage circuit of the interior lamp relay. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 40

--

33

Replace the INT LP relay. Refer to Wiring Repairs in Wiring Systems.

Did you complete the replacement?

Go to Step 40

--

34

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

Did you complete the replacement?

Go to Step 40

--

35

Replace the door control module. Refer to Door Control Module Replacement in Doors.

Did you complete the replacement?

Go to Step 40

--

36

Replace interior lamp switch. Refer to Interior Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 40

--

37

Important:: Perform the setup procedure for the IPM after IPM replacement.

Replace the IPM. Refer to Instrument Panel Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 40

--

38

Important:: Perform the setup procedure for the RIM after RIM replacement.

Replace the RIM. Refer to Rear Integration Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 40

--

39

Replace the inoperative courtesy lamp bulb.

Did you complete the replacement?

Go to Step 40

--

40

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2