GM Service Manual Online
For 1990-2009 cars only

Courtesy Lamps Inoperative with Doors Open With Door Jamb Switches

Step

Action

Value(s)

Yes

No

Important: To prevent misdiagnosis, check for body control module (BCM) diagnostic trouble codes (DTCs). Refer to Body Control Systems.

1

Open both of the doors.

Are the courtesy lamps on?

--

Go to Step  2

Go to Step  9

2

  1. Open each door, one at a time, in order to determine which is inoperative.
  2. Using a fused jumper connected to ground, backprobe the body control module (BCM) connector C3 terminal D11 (driver door) or terminal D12 (passenger door).

Are the courtesy lamps on?

--

Go to Step  4

Go to Step  3

3

  1. Test for a poor connection at BCM connector C3 terminal D11 (driver door) or terminal D12.
  2. If the connection is OK, replace the BCM. Refer to Body Control Module Replacement

Is the repair complete?

--

System OK

--

4

Using a fused jumper connected to ground, backprobe connector C200C terminal 4 (driver door) or terminal 5 (passenger door).

Are the courtesy lamps on?

--

Go to Step  5

Go to Step  6

5

  1. Disconnect the inoperative door jamb switch.
  2. Connect a fused jumper from the door jamb switch connector terminal to ground.

Are the courtesy lamps on?

--

Go to Step  8

Go to Step  7

6

  1. Test for a poor connection at connector C200.
  2. If the connection is OK, repair the open in circuit 745 (driver door) or 746 (passenger door) between connector C200 and the BCM.

Is the repair complete?

--

System OK

--

7

  1. Test for a poor connection at connector C200.
  2. If the connection is OK, repair the open in circuit 745 (driver door) or 746 (passenger door) between connector C200 and the front side door lock.

Is the repair complete?

--

System OK

--

8

  1. Test for a poor connection at the door jamb switch.
  2. Check the door jamb switch for a poor ground.
  3. If the connection and ground are OK, replace the door jamb switch.

Is the repair complete?

--

System OK

--

9

Turn on the rearview mirror courtesy/reading lamp switches.

Are the courtesy/reading lamps on?

--

Go to Step 10

Go to Step 11

10

Repair the open in CKT 149 between the BCM and S241.

Is the repair complete?

--

System OK

--

11

Repair the open in CKT156 between the BCM and S247.

Is the repair complete?

--

System OK

--

Courtesy Lamps Inoperative with Doors Open Without Door Jamb Switches

Step

Action

Value(s)

Yes

No

Important: To prevent misdiagnosis, check for body control module (BCM) diagnostic trouble codes (DTCs). Refer to Body Control Systems.

1

Open both of the doors.

Are the courtesy lamps on?

--

Go to Step 2

Go to Step 11

2

  1. Open each door, one at a time, in order to determine which is inoperative.
  2. Using a fused jumper connected to ground, backprobe the body control module (BCM) connector C3 terminal D11 (driver door) or terminal D12 (passenger door).

Are the courtesy lamps on?

--

Go to Step 4

Go to Step 3

3

  1. Test for a poor connection at BCM connector C3 terminal D11 (driver door) or terminal D12.
  2. If the connection is OK, replace the BCM. Refer to Body Control Module Replacement .

Is the repair complete?

--

System OK

--

4

Using a fused jumper connected to ground, backprobe connector C200C terminal 4 (driver door) or terminal 5 (passenger door).

Are the courtesy lamps on?

--

Go to Step 5

Go to Step 6

5

  1. Disconnect the inoperative front side door lock.
  2. Connect a fused jumper from side door lock switch terminal A to ground.

Are the courtesy lamps on?

--

Go to Step 8

Go to Step 7

6

  1. Test for a poor connection at connector C200.
  2. If the connection is OK, repair the open in circuit 745 (driver door) or 746 (passenger door) between connector C200 and the BCM.

Is the repair complete?

--

System OK

--

7

  1. Test for a poor connection at connector C200.
  2. If the connection is OK, repair the open in circuit 745 (driver door) or 746 (passenger door) between connector C200 and the front side door lock.

Is the repair complete?

--

System OK

--

8

  1. Reconnect the front side door lock.
  2. Open the inoperative door.
  3. Using a fused jumper connected to ground, backprobe the front side door lock connector terminal D.

Are the courtesy lamps on?

--

Go to Step 9

Go to Step 10

9

Repair the open in circuit 750 between the front side door lock and S220.

Is the repair complete?

--

System OK

--

10

  1. Test for a poor connection at the front side door lock.
  2. If the connection is OK, replace the front side door lock.

Is the repair complete?

--

System OK

--

11

Turn on the rearview mirror courtesy/reading lamp switches.

Are the courtesy reading lamps on?

--

Go to Step 12

Go to Step 13

12

Repair the open in circuit 149 between the BCM and S241.

Is the repair complete?

--

System OK

--

13

Repair the open in circuit 156 between the BCM and S247.

Is the repair complete?

--

System OK

--