Test B: One Low Beam Headlamp Is Inoperative

PINPOINT TEST B: ONE LOW BEAM HEADLAMP IS INOPERATIVE

B1-B3:

B3-B5:

B5-B7:

B8-B9:

B9-B11:

B12:

Normal Operation - Expedition
When the smart junction box (SJB) detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the SJB provides voltage through circuits CLF04 (BN/BU) and CLF05 (BU/GN) to the LH and RH low beam headlamps, respectively. Ground is supplied on circuits GD120 (BK/GN) and GD123 (BK/GY) for the LH and RH headlamps, respectively.

Normal Operation - Navigator
When the SJB detects the headlamp switch in the HEADLAMPS ON position and the multifunction switch in the LOW BEAM position, the SJB provides voltage through circuits CLF04 (BN/BU) and CLF05 (BU/GN) to the LH and RH high intensity discharge (HID) relay coils, respectively. Ground for the HID relay coils is provided through circuit GD123 (BK/GY). Switched voltage for the LH and RH HID relays is provided from the battery junction box (BJB) through circuits SBB44 (GN/RD) and SBB48 (VT/RD), respectively. When the relays are energized, voltage is routed to the LH and RH headlamps through circuits CLF30 (VT/BN) and CLF31 (YE/GY), respectively. Ground is supplied on circuits GD120 (BK/GN) and GD123 (BK/GY) for the LH and RH headlamps, respectively. The ballasts within each headlamp steps up the voltage needed to illuminate the HID bulbs.

DTC B2A2E - is an on-demand DTC that sets when the SJB detects an open in the RH low beam output circuit.

DTC B2A2F - is a continuous and on-demand DTC that sets when the SJB detects a short to ground in the RH low beam output circuit.

DTC B2A30 - is an on-demand DTC that sets when the SJB detects an open in the LH low beam output circuit.

DTC B2A31 - is a continuous and on-demand DTC that sets when the SJB detects a short to ground in the LH low beam output circuit.

Possible Causes
- Fuse
- Circuit CLF04 (BN/BU) open or short to ground
- Circuit CLF05 (BU/GN) open or short to ground
- Circuit CLF30 (VT/BN) open
- Circuit CLF31 (YE/GY) open
- Circuit GD120 (BK/GN) open
- Circuit GD123 (BK/GY) open
- Circuit SBB44 (GN/RD) open
- Circuit SBB48 (VT/RD) open
- HID relay
- HID bulb
- Ballast
- Headlamp assembly
- SJB