Headlamp LO Does Not Illuminate (Both Sides)

WARNING: This page is about a different car, the 2005 Nissan Quest. 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.

Fig 1: Displaying HEAD LAMP SW 1 And HEAD LAMP SW 2 On DATA MONITOR MODE Screen
Courtesy of NISSAN MOTOR CO., U.S.A.

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 ".
HEADLAMP ACTIVE TEST
1. Select "IPDM E/R" on CONSULT-II, and select "ACTIVE TEST" on "SELECT DIAG MODE" screen.
2. Select "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: Displaying LO On ACTIVE TEST Screen
  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: Displaying HL LO REQ' On DATA MONITOR Mode Screen
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK HEADLAMP INPUT SIGNAL
1. Turn ignition switch OFF.
2. Disconnect headlamp RH and LH connectors.
3. Select "IPDM E/R" on CONSULT-II, and select "ACTIVE TEST" on "SELECT DIAG MODE" screen.
4. Select "LAMPS" on "SELECT TEST ITEM" screen.
5. Touch "LO" on "ACTIVE TEST" screen.
6. When headlamp low beam is operating, check voltage between headlamp RH and LH harness connectors and ground.
  
  Fig 4: Terminals Voltage Reference Chart
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Fig 5: Checking Voltage Between Headlamp RH/LH Harness Connectors Terminal 1 & 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 E122 terminal 20 (R/Y) and headlamp RH harness connector E12 terminal 1 (R/Y).
  20 (R/Y) - 1 (R/Y): Continuity should exist.
4. Check continuity between IPDM E/R harness connector E122 terminal 30 (L) and headlamp LH harness connector E44 terminal 1 (L).
  30 (L) - 1 (L): Continuity should exist.
  
  Fig 6: Checking Continuity Between IPDM E/R Harness Connector E122 Terminal 20 Or 30 & Headlamp LH Harness Connector E44 Terminal 1
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: Replace IPDM E/R. Refer to "REMOVAL AND INSTALLATION OF IPDM E/R ".
- NG: Repair harness or connector.
CHECK HEADLAMP GROUND
1. Turn ignition switch OFF.
2. Check continuity between headlamp RH harness connector E12 terminal 2 (B) and ground.
  2 (B) - Ground: Continuity should exist.
3. Check continuity between headlamp LH harness connector E44 terminal 2 (B) and ground.
  2 (B) - Ground: Continuity should exist.
  
  Fig 7: Checking Continuity Between Headlamp Harness Connectors E12 Or E44 Terminal 2 & Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG
- OK: Check headlamp connector for damage or poor connection. Repair as necessary.
- NG: Repair harness or connector.