Headlamp LO Does Not Illuminate (Both Sides)

WARNING: This page is about a different car, the 2005 Infiniti QX56. However, it is still accessible from the selected car via links, so may be relevant.

CHECK COMBINATION SWITCH INPUT SIGNAL
Select "BCM" on CONSULT-II. With "HEAD LAMP" data monitor, make sure "HEAD LAMP SW 1" and "HEAD LAMP SW 2" turns ON-OFF linked with operation of lighting switch.
- When lighting switch is in: HEAD LAMP SW 1 ON
- 2ND position: HEAD LAMP SW 2 ON
OK or NG
- OK: GO TO 2.
- NG: Check lighting switch. Refer to "COMBINATION SWITCH INSPECTION ".
Fig 1: Identifying "HEAD LAMP SW 1" And "HEAD LAMP SW 2"
Courtesy of NISSAN MOTOR CO., U.S.A.
HEADLAMP ACTIVE TEST
1. Select "IPDM E/R" on CONSULT-II, and select "ACTIVE TEST" on "SELECT DIAG MODE" screen.
2. Select "EXTERNAL LAMPS" on "SELECT TEST ITEM" screen.
3. Touch "LO" on "ACTIVE TEST" screen.
4. Make sure headlamp low beam operates.
  - Headlamp low beam should operate.
OK or NG
- OK: GO TO 3.
- NG: GO TO 4.
Fig 2: Identifying "ACTIVE TEST" Mode
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK IPDM E/R
1. Select "IPDM E/R" on CONSULT-II, and select "DATA MONITOR" on "SELECT DIAG MODE" screen.
2. Make sure "HL LO REQ" turns ON when lighting switch is in 2ND position.
  - When lighting switch is in 2ND position: HL LO REQ ON
  OK or NG
  - OK: Replace IPDM E/R. Refer to "REMOVAL AND INSTALLATION OF IPDM E/R ".
  - NG: Replace BCM. Refer to "REMOVAL AND INSTALLATION OF BCM ".
  Fig 3: Identifying "HL LO REQ" Turned "ON"
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HEADLAMP INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect front combination lamp RH and LH connector.
3. Turn ignition switch ON.
4. Select "IPDM E/R" on CONSULT-II, and select "ACTIVE TEST" on "SELECT DIAG MODE" screen.
5. Select "EXTERNAL LAMPS" on "SELECT TEST ITEM" screen.
6. Touch "LO" on "ACTIVE TEST" screen.
7. When headlamp low beam is operating, check voltage between front combination lamp RH and LH harness connector and ground.
  
  Fig 4: Front Combination Lamp RH, LH Harness Connector And Ground Voltage Specification Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 5: Checking Voltage Between Front Combination Lamp RH, LH Harness Connector And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: GO TO 6.

NG: GO TO 5.
CHECK HEADLAMP CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect IPDM E/R connector.
3. Check continuity between IPDM E/R harness connector E123 terminal 54 (R/Y) and front combination lamp RH harness connector E107 terminal 5 (R/Y).
  - 54 (R/Y) - 5 (R/Y): Continuity should exist.
4. Check continuity between IPDM E/R harness connector E123 terminal 52 (L) and front combination lamp LH harness connector E11 terminal 5 (L).
  - 52 (L) - 5 (L): Continuity should exist.
OK or NG
- OK: Replace IPDM E/R. Refer to "REMOVAL AND INSTALLATION OF IPDM E/R ".
- NG: Repair harness or connector.
Fig 6: Checking Continuity Between IPDM E/R Harness Connector E123 Terminal 52 And Front Combination Lamp LH Harness Connector E11 Terminal 5
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HEADLAMP GROUND
1. Turn ignition switch OFF.
2. Check continuity between front combination lamp RH harness connector E107 terminal 1 (B) and ground.
  - 1 (B) - Ground: Continuity should exist.
3. Check continuity between front combination lamp LH harness connector E11 terminal 1 (B) and ground.
  - 1 (B) - Ground: Continuity should exist.
OK or NG
- OK: Check front combination lamp connector for damage or poor connection, ballasts (HID control unit) and xenon bulbs. Repair as necessary.
- NG: Repair harness or connector.
Fig 7: Checking Continuity Between Front Combination Lamp LH Harness Connector E11 Terminal 1 And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.