For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Diagnostic Fault Information

Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance
--- | --- | --- | --- | ---
CTSY/TRN SIG RT FRT Fuse B+ Terminal 2 X4 | B2615 00 | B2615 00 | -- | --
INADV/PWR/LED Fuse B+ Terminal 2 X3 | 5 | 5 | 5 | --
Courtesy Lamp Defeat Signal | 4 | 4 | 4 | --
Courtesy Lamps Control | B2615 00 | B2615 00 | B2615 00 | --
Console Compartment Lamp Switch Ground | -- | 7 | -- | --
Courtesy Lamp Defeat Ground | -- | 4 | -- | --
Courtesy Lamp - Left Footwell | -- | 1 | -- | --
Courtesy Lamp - Right Footwell | -- | 1 | -- | --
Door Courtesy Lamp Ground - Left Front | -- | 1 | -- | --
Door Courtesy Lamp Ground - Left Rear | -- | 1 | -- | --
Door Courtesy Lamp Ground - Right Front | -- | 1 | -- | --
Door Courtesy Lamp Ground - Right Rear | -- | 1 | -- | --
Dome/Reading Lamps Ground | -- | 2 | -- | --
Dome Lamp - Front Ground | -- | 1 | -- | --
Dome Lamp - Rear Ground | -- | 1 | -- | --
Ignition Key Cylinder Lamp Ground | -- | 1 | -- | --
I/P Compartment Lamp Switch Ground | -- | 8 | -- | --
Sunshade - Left Ground | -- | 3 | -- | --
Sunshade - Right Ground | -- | 3 | -- | --
Rear Compartment Courtesy Lamp Ground | -- | 6 | -- | --
1. Courtesy Lamps Malfunction 2. Dome Lamp Switch Malfunction 3. Sunshade Lamps Malfunction 4. Courtesy Lamp Defeat Malfunction 5. Reading Lamps Malfunction

6. Rear Compartment Lamp Malfunction

7. Console Compartment Lamp Malfunction

8. I/P Compartment Lamp Malfunction

### Circuit/System Description

The body control module (BCM) applies battery voltage to the courtesy lamps through 2 separately controlled courtesy lamp supply voltage circuits. When any door is opened, the door ajar switch contacts close and the BCM receives a door-ajar input. If the BCM receives a door lock or unlock input or a rear hatch open input, the BCM will activate the courtesy lamp supply voltage circuits, providing battery voltage to all of the dome/reading lamps, ignition key cylinder lamp, rear compartment lamp, sunshade lamps footwell lamps, and courtesy lamps. In the event that any of these lamps were to remain illuminated for more than 20 minutes with the ignition switch in the OFF position, the BCM will deactivate the courtesy lamp control circuits to prevent a total battery discharge condition.

### Reference Information

#### Schematic Reference

Interior Lights Schematics

#### Connector End View Reference

Component Connector End Views

#### Description and Operation

Interior Lighting Systems Description and Operation

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

#### Scan Tool Reference

Control Module References for scan tool information

### Circuit/System Verification

1. Ignition ON, doors CLOSED, observe the scan tool Interior Lamp Activation Reason parameter while turning the courtesy lamp defeat switch ON and OFF. The parameter should change between Off and Manual Defeat.

⇒ | If the parameter does not change between the commanded states, refer to Dome Lamp Defeat Switch Malfunction.

2. Ignition ON, courtesy lamp defeat switch OFF, observe the scan tool Interior Lamp Activation Reason parameter while opening and closing each door. The parameter should change between Door Open and Door Closed.

⇒ | If the parameter does not change as each door is opened and closed, refer to Door Ajar Indicator Malfunction.

3. Operate the dome lamp switch On and Off. The dome lamps should turn On and Off as the switch is activated.

⇒ | If the dome lamps do not turn On and Off as the switch is activated, refer to Dome Lamp Switch Malfunction.

4. Command the Interior Lamp Test ON and OFF with a scan tool. The courtesy lamps should turn ON and OFF when changing between the commanded states.

⇒ | If the courtesy lamps do not turn On and Off when commanded, refer to Courtesy Lamps Malfunction.

### Circuit/System Testing

#### Dome Lamp Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the front dome lamp.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohms between the ground circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp does not illuminate between the signal circuit terminal 2 and ground.

⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.

4. Test for B+ between the signal circuit terminal 2 and ground.

⇒ | If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the dome lamp.

#### Dome Lamp Defeat Switch Malfunction

1. Ignition OFF, disconnect the harness connector at the front dome lamp.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohms between the ground circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, verify that a test lamp does not illuminate between the signal circuit terminal 3 and ground.

⇒ | If the test lamp illuminates, test the signal circuit for a short to voltage. If the circuit tests normal, replace the BCM.

4. Test for B+ between the signal circuit terminal 3 and ground.

⇒ | If not the specified value, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the dome lamp.

#### Courtesy Lamps Malfunction

1. Ignition OFF, disconnect the harness connector at the inoperative courtesy lamp.
2. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohms between the appropriate ground circuit terminal listed below and ground.

• | Dome/reading lamp - front terminal 1

• | Dome/reading lamp - rear terminal 1

• | Ignition key cylinder lamp terminal B

• | Courtesy lamp - left footwell terminal 2

• | Courtesy lamp - right footwell terminal 2

• | Courtesy lamp - LF door terminal A X2

• | Courtesy lamp - LR door terminal A X2

• | Courtesy lamp - RF door terminal A X2

• | Courtesy lamp - RR door terminal A X2

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect a test lamp between the appropriate control circuit terminal listed below and ground.

• | Dome/reading lamp - front terminal 4

• | Dome/reading lamp - rear terminal 2

• | Ignition key cylinder lamp terminal A

• | Courtesy lamp - left footwell terminal 1

• | Courtesy lamp - right footwell terminal 1

• | Courtesy lamp - LF door terminal A X1

• | Courtesy lamp - LR door terminal A X1

• | Courtesy lamp - RF door terminal A X1

• | Courtesy lamp - RR door terminal A X1

4. Command the Interior Lamp Test ON and OFF with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.

⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM.

⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

5. If all circuits test normal, replace the inoperative courtesy lamp.

#### Reading Lamps Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the BCM.
4. Disconnect the harness connector at the inoperative dome/reading lamp assembly.
5. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohms between the ground circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

6. Ignition ON, verify that a test lamp illuminates between the appropriate control circuit terminal listed below and ground.

• | Dome/reading lamp - front terminal 5

• | Dome/reading lamp - rear terminal 3

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. Remove the INADV/PWR/LED fuse and verify the test lamp turns OFF.

⇒ | If the test lamp remains illuminated, test the appropriate control circuit terminal listed below for a short to voltage. If the circuit tests normal, replace the BCM.

• | Dome/reading lamp - front terminal 5

• | Dome/reading lamp - rear terminal 3

8. If all circuits test normal, replace the inoperative dome/reading lamp assembly.

#### Rear Compartment Courtesy lamp Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the BCM.
4. Disconnect the X1 and X2 harness connectors at the rear compartment courtesy lamp.
5. Ignition OFF, trunk OPEN, test for less than 1 ohm between the control circuit terminal A X2 and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the rear compartment lid latch.

6. Ignition ON, verify that a test lamp illuminates between the control circuit terminal A X1 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. Remove the INADV/PWR/LED fuse and verify the test lamp turns OFF.

⇒ | If the test lamp remains illuminated, test the control circuit terminal A X1 for a short to voltage. If the circuit tests normal, replace the BCM.

8. Ignition OFF, connect the X1 and X2 harness connectors at the rear compartment courtesy lamp. Disconnect the harness connector at the rear compartment lid latch.
9. Ignition ON, verify that a test lamp illuminates between the control circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance.

10. If all circuits test normal, replace the rear compartment courtesy lamp.

#### Sunshade Lamps Malfunction

1. Ignition OFF, disconnect the X3 harness connector at the BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Ignition OFF, connect the X3 harness connector at the BCM.
4. Ignition OFF, disconnect the harness connector at the inoperative sunshade lamp.
5. Ignition OFF, scan tool OFF, doors CLOSED, interior lamps OFF, test for less than 5 ohms between the ground circuit terminal 1 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

6. Ignition ON, verify that a test lamp illuminates between the control circuit terminal 2 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. Remove the INADV/PWR/LED and verify the test lamp turns OFF.

⇒ | If the test lamp remains illuminated, test the control circuit terminal 2 for a short to voltage. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, replace the inoperative sunshade lamp assembly.

#### Console Compartment Lamp Malfunction

1. Ignition OFF, disconnect the X2 harness connectors at the console compartment lamp switch.
2. Ignition OFF, test for less than 1 ohm between the ground circuit terminal A X2 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect the X2 harness connectors at the console compartment lamp switch.
4. Ignition OFF, disconnect the X1 and X2 harness connectors at the console compartment lamp.
5. Ignition OFF, console compartment OPEN, test for less than 1 ohm between the control circuit terminal A X2 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the console compartment lamp switch.

6. Verify that a test lamp illuminates between the control circuit terminal A X1 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. Remove the INADV/PWR/LED and verify the test lamp turns OFF.

⇒ | If the test lamp remains illuminated, test the control circuit terminal A X1 for a short to voltage. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, replace the console compartment lamp.

#### I/P Compartment Lamp Malfunction

1. Ignition OFF, disconnect the X2 harness connectors at the I/P compartment lamp switch.
2. Ignition OFF, test for less than 1 ohm between the ground circuit terminal A X2 and ground.

⇒ | If greater than the specified range, test the ground circuit for an open/high resistance.

3. Connect the X2 harness connectors at the I/P compartment lamp switch.
4. Disconnect the X1 and X2 harness connectors at the I/P compartment lamp.
5. Ignition OFF, I/P compartment OPEN, test for less than 1 ohm between the control circuit terminal A X2 and ground.

⇒ | If greater than the specified range, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the I/P compartment lamp switch.

6. Verify that a test lamp illuminates between the control circuit terminal A X1 and ground.

⇒ | If the test lamp does not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM.

7. Remove the INADV/PWR/LED and verify the test lamp turns OFF.

⇒ | If the test lamp remains illuminated, test the control circuit terminal A X1 for a short to voltage. If the circuit tests normal, replace the BCM.

8. If all circuits test normal, replace the I/P compartment lamp.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

• | Ignition Lock Cylinder Bulb Replacement

• | Console Lamp Replacement

• | Dome Lamp Replacement

• | Vanity Mirror Lamp Replacement

• | Rear Compartment Courtesy Lamp Replacement

• | Instrument Panel Compartment Lamp Replacement

• | Instrument Panel Compartment Lamp Switch Replacement

• | Door Courtesy Lamp and Reflector Replacement

• | Control Module References for BCM replacement, setup, and programming