GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

DEFINITION: The interior courtesy lights stay on with all of the doors closed, the instrument panel (IP) switch off, the interior lamps override switch in the ON position (interior lights enabled), and none of the interior lighting modes activated. However, the inadvertent load (battery rundown) protection turns off the interior courtesy lights after 10 minutes or 3 minutes on vehicles with less than 24 accumulated kilometers (15 miles).

1

Was the Body Control Module (BCM) Diagnostic System Check performed?

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Go to Step 2

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

2

Perform the BCM Input/Output test:

  1. Turn off the IP dimmer switch.
  2. Turn ON the interior lamps override switch (interior courtesy lamps enabled).
  3. Turn the ignition switch to the LOCK position.
  4. Remove the BCM PRGRM fuse.
  5. Turn the ignition switch to the ACC position. The BCM sounds 4 chimes, indicating the BCM type installed on the vehicle.
  6. Within 1 second, turn the ignition switch from the ACC position to the LOCK position and back to the ACC position.
  7. The BCM sounds any stored DTCs.

  8. Turn the I/P dimmer switch to the DOME position.
  9. The BCM enters the Input/Output test.

  10. Cycle the IP dimmer switch from the DOME position to the OFF position and back to the DOME position in order to move to the next test.
  11. The BCM runs the Input/Output test in numerical order.

    The BCM flashes the fasten belts indicator and sounds the chime a number equivalent to the Input/Output test number:

    • Test 1 de-energizes CKT 1393 (protected courtesy light output).
    • Test 2 energizes CKT 1393.
    • Test 3 grounds CKT 690 (courtesy lights control).
    • Test 4 turns on the exterior lights.
    • Test 5 sounds the horn relay for 25 ms.
    • Test 6 turns on the security indicator lamp.
    • Test 7 turns off the theft security indicator lamp.

NOTE: While the BCM is performing the Input/Output test, the chime sounds when any of the BCM inputs is activated. Example: The chime sounds when any door is opened.

Does the BCM enter the Input/Output test?

--

Go to Step 3

Go to Step 6

3

Cycle the IP dimmer switch from the DOME position to the OFF position and back to the DOME position in order to move to test 1.

Do all of the interior lights turn off when the BCM performs the Input/Output test 1?

--

Go to Step 4

Go to Step 7

4

  1. Close all of the vehicle doors.
  2. Open and close the left front and the right front doors, one door at a time.
  3. Open and close the left sliding door (if equipped) and the right sliding door, one door at a time.
  4. Open and close the rear liftgate door.

Does the chime sound when each vehicle door opens?

--

Go to Step 5

Go to Step 8

5

  1. Go to Step 19 if the vehicle is not equipped with the content theft deterrent (RPO UA6).
  2. Insert the key into the driver door lock.
  3. Turn the key until the key stops (as in trying to unlock the door) while listening for the chime.
  4. Remove the key from the driver door lock.

Does the chime sound when the key is turned?

--

Go to Step 19

Go to Step 16

6

  1. Turn off the IP dimmer switch.
  2. Disconnect the BCM connector C2.
  3. Use a J 39200 digital multimeter (DMM) in order to measure the resistance between the BCM harness connector C2 terminal C2 and ground.

Is the resistance infinite?

Infinite

Go to Step 19

Go to Step 18

7

  1. Disconnect the BCM connector C1.
  2. Verify that all of the roof rail reading lamps are turned off.
  3. Verify that the sunshade mirror covers are closed.
  4. Use the J 39200 DMM in order to measure the resistance between the BCM harness connector C1 terminal F and ground.

Is the resistance infinite?

Infinite

Go to Step 19

Go to Step 20

8

  1. Close the driver door.
  2. Disconnect the BCM connector C2.
  3. Use the J 39200 DMM in order to measure the resistance between the BCM harness connector C2 terminal C1 and ground (leave the J 39200 DMM in place after the measurement is made).

Is the resistance infinite?

Infinite

Go to Step 10

Go to Step 9

9

  1. Disconnect the left front driver door lock switch electrical connector.
  2. Use the J 39200 DMM in order to measure the resistance again.

Is the resistance infinite?

Infinite

Go to Step 21

Go to Step 22

10

  1. Close the right front door.
  2. Close the rear liftgate door.
  3. Use the J 39200 DMM in order to measure the resistance between the BCM harness connector C2 terminal C3 and ground (leave the J 39200 DMM in place after the measurement is taken).

Is the resistance infinite?

Infinite

Go to Step 13

Go to Step 11

11

  1. Disconnect the right front door lock switch.
  2. Use the J 39200 DMM in order to measure the resistance again.
  3. Leave the J 39200 DMM in place after the measurement is taken if the resistance is not infinite.

Is the resistance infinite?

Infinite

Go to Step 21

Go to Step 12

12

  1. Disconnect the rear liftgate door ajar switch electrical connector.
  2. Use the J 39200 DMM in order to measure the resistance again.

Is the resistance infinite?

Infinite

Go to Step 23

Go to Step 24

13

  1. Close the sliding door(s).
  2. Use the J 39200 DMM in order to measure the resistance between the BCM connector C2 terminal C4 and ground (leave the J 39200 DMM in place after the measurement is taken).

Is the resistance infinite?

Infinite

Go to Step 18

Go to Step 14

14

  1. Disconnect the right sliding door jamb switch electrical connector.
  2. Disconnect the right sliding door jamb switch electrical connector.
  3. Use the J 39200 DMM in order to measure the resistance again.
  4. Leave the J 39200 DMM in place after the measurement is taken if the resistance is not infinite.

Is the resistance infinite?

Infinite

Go to Step 25

Go to Step 15

15

  1. Go to Step 26 if the vehicle is not equipped with a left sliding door.
  2. Disconnect the left sliding door jamb switch electrical connector.
  3. Use the J 39200 DMM in order to measure the resistance again.

Is the resistance infinite?

Infinite

Go to Step 25

Go to Step 26

16

  1. Verify that the key is removed from all of the door locks.
  2. Disconnect the BCM connector C2.
  3. Use the J 39200 DMM in order to measure the resistance between the BCM harness connector C2 terminal C5 and ground.
  4. Leave the J 39200 DMM in place after the measurement is taken if the resistance is not infinite.

Is the resistance infinite?

Infinite

Go to Step 19

Go to Step 17

17

  1. Disconnect the following lock switch electrical connectors, one at a time until, the J 39200 DMM reads infinite:
  2. • The left front
    • Refer to Front Side Door Lock Replacement in Doors.
    • The right front
    • Refer to Front Side Door Lock Replacement in Doors.
    • The rear liftgate
    •  Refer to Liftgate Latch Replacement in Body Rear End.
  3. If the J 39200 DMM shows infinite upon disconnecting one of the lock cylinder switches, replace that lock cylinder switch. Refer to Front Side Door Lock Replacement in Doors.
  4. If the J 39200 DMM does not show infinite after all of the lock cylinder switches are disconnected, repair a short to ground in CKT 781.

Is the repair complete?

--

Go to Step 29

--

18

  1. Disconnect the headlamp and the IP lamp dimmer switch electrical connector.
  2. Use the J 39200 DMM in order to measure the resistance again.

Is the resistance infinite?

Infinite

Go to Step 27

Go to Step 28

19

  1. Inspect the BCM connectors for faulty terminal contact.
  2. If the BCM connectors are OK, replace the BCM. Refer to Body Control Module Replacement

Is the repair complete?

--

Go to Step 29

--

20

Repair a short to ground in CKT 690.

Is the repair complete?

--

Go to Step 29

21

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

Is the repair complete?

--

Go to Step 29

--

22

Repair a short to ground in CKT 159.

Is the repair complete?

--

Go to Step 29

--

23

Replace the rear liftgate door lock switch. Refer to Liftgate Latch Replacement in Body Rear End.

Is the repair complete?

--

Go to Step 29

--

24

Repair a short to ground in CKT 49.

Is the repair complete?

--

Go to Step 29

--

25

Replace the sliding door jamb switch. Refer to Door Jamb Switch Replacement - Sliding Door in Doors.

Is the repair complete?

--

Go to Step 29

--

26

Repair a short to ground in CKT 54.

Is the repair complete?

--

Go to Step 29

--

27

Replace the headlamp and the IP lamp dimmer switch. Refer to Headlamp Switch Replacement .

Is the repair complete?

--

Go to Step 29

--

28

Repair a short to ground in CKT 156.

Is the repair complete?

--

Go to Step 29

--

29

  1. Turn the ignition switch to the LOCK position.
  2. Reinstall the connectors/components that were 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 the 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?

--

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

System OK