GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Interior Lights Schematics

1

Did you perform the Lighting Systems Diagnostic System Check?

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

  1. Turn the ignition ON.
  2. Place the IP dimmer switch in the ON position.
  3. Close all of the doors.
  4. Observe the courtesy lamps.

Do all of the courtesy lamps illuminate?

Go to Step 4

Go to Step 3

3

Is only one courtesy lamp inoperative?

Go to Step 14

Go to Step 8

4

  1. Place the IP dimmer switch in the OFF position.
  2. Open the driver side door.
  3. Observe the courtesy lamps.

Do the courtesy lamps illuminate?

Go to Step 5

Go to Step 12

5

  1. Close the driver side door.
  2. Open the passenger side door.
  3. Observe the courtesy lamps.

Do the courtesy lamps illuminate?

Go to Step 6

Go to Step 13

6

  1. Close the passenger side door.
  2. Open the rear compartment.
  3. Observe the courtesy lamps.

Do the courtesy lamps illuminate?

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

Go to Step 7

7

Is the HATCH AJAR indicator on?

Go to Step 20

Go to Trunk Ajar Indicator Inoperative in Body Rear End

8

  1. Place the IP dimmer switch in the OFF position.
  2. Open the driver side door.
  3. Observe the courtesy lamps.

Do the courtesy lamps illuminate?

Go to Step 9

Go to Step 16

9

  1. Turn the ignition OFF.
  2. Disconnect the BCM connector.
  3. Place the IP dimmer switch in the ON position.
  4. Probe the interior lamps control circuit of the BCM with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 32

Go to Step 10

10

  1. Disconnect the headlamp switch connector.
  2. Probe the ground circuit of the headlamp switch with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 11

Go to Step 26

11

  1. Connect the headlamp switch connector.
  2. Place the IP dimmer switch in the ON position.
  3. Backprobe the interior lamp control circuit of the headlamp switch with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 28

Go to Step 30

12

  1. Turn the ignition OFF.
  2. Disconnect the BCM connector.
  3. Open the driver side door.
  4. Probe the driver door ajar switch signal circuit of the BCM with a test lamp that is connected battery positive voltage.

Does the test lamp illuminate?

Go to Step 32

Go to Step 17

13

  1. Turn the ignition OFF.
  2. Disconnect the BCM connector.
  3. Open the passenger side door.
  4. Probe the passenger door ajar switch signal circuit of the BCM with a test lamp that is connected battery positive voltage.

Does the test lamp illuminate?

Go to Step 32

Go to Step 18

14

Probe the courtesy lamps supply voltage circuit of the inoperative courtesy lamp with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 15

Go to Step 24

15

Probe between the courtesy lamps low control circuit and the courtesy lamps supply voltage circuit of the inoperative courtesy lamp with a test lamp.

Does the test lamp illuminate?

Go to Step 29

Go to Step 25

16

  1. Open the driver side door.
  2. Probe the courtesy lamps supply voltage circuit of one of the courtesy lamp with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 19

Go to Step 21

17

  1. Disconnect the driver door lock connector.
  2. Probe the ground circuit of the driver door lock connector with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 22

Go to Step 27

18

  1. Disconnect the passenger door lock connector.
  2. Probe the ground circuit of the passenger door lock connector with a test lamp that is connected to battery positive voltage.

Does the test lamp illuminate?

Go to Step 23

Go to Step 27

19

Test for an open or high resistance in the courtesy lamps low control circuit of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 32

20

Test for an open or high resistance in the rear compartment lid ajar input circuit of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 32

21

Test for an open or high resistance in the courtesy lamps supply voltage circuit of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 32

22

Test for an open or high resistance in the driver door ajar switch signal circuit of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 31

23

Test for an open or high resistance in the passenger door ajar switch signal circuit of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and to Circuit Testing in Wiring Systems.

Did you find and correct the condition?

Go to Step 33

Go to Step 31

24

Repair the open or high resistance in the courtesy lamp supply voltage circuit of the inoperative courtesy lamp. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 33

--

25

Repair the open or high resistance in the courtesy lamp low control circuit of the inoperative courtesy lamp. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 33

--

26

Repair the open or high resistance in the ground circuit of the headlamp switch. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 33

--

27

Repair the open or high resistance in the ground circuit of the door lock. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 33

--

28

Repair the open or high resistance in the interior lamps control circuit of the BCM. Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

Go to Step 33

--

29

Replace the inoperative courtesy lamp. Refer to the appropriate procedure:

    •  Dome Lamp Replacement

Is the replacement complete?

Go to Step 33

--

30

Replace the headlamp switch. Refer to Headlamp Switch Replacement .

Is the replacement complete?

Go to Step 33

--

31

Replace the inoperative door lock. Refer to Door Lock Replacement in Doors.

Is the replacement complete?

Go to Step 33

--

32

Important: Perform the set up procedure for the body control module. Refer to Body Control Module (BCM) Programming/RPO Configuration in Body Control System.

Replace the BCM. Refer to Body Control Module Replacement in Body Control System.

Did you complete the replacement?

Go to Step 33

--

33

Operate the system to verify the repair.

Did you correct the condition?

System OK

Go to Step 2