Test F: The Headlamps Are On Continuously

PINPOINT TEST F: THE HEADLAMPS ARE ON CONTINUOUSLY

Normal Operation
The smart junction box (SJB) sends voltage reference signals to the headlamp switch through circuits 1400 (TN/WH), 1401 (BK/LG), and 1402 (RD/WH). At any given time, the headlamp switch routes one of the input circuits to ground through circuit 1205 (BK).

When the SJB detects the headlamp switch in the HEADLAMPS ON position (or a fault with the headlamp switch inputs) and the multifunction switch in the LOW BEAM position, the SJB sends voltage through circuits 1338 (WH) and 1336 (LG/WH) to the LH and RH low beams, or the LH and RH high intensity discharge (HID) relays (if equipped), respectively.

When the HID relays are energized, voltage is routed to the LH and RH headlamps through circuits 2008 (PK/BK) and 2009 (PK/WH), respectively.

The SJB also sends a voltage reference signal to the multifunction switch through circuits 1394 (WH/RD) and 1395 (RD/PK). When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the signal is routed back to the SJB (ground internal to the SJB). When the SJB detects a request for flash-to-pass or high beams, the SJB provides ground to the high beam relay through circuit 1708 (LG/BK). When the high beam relay is energized, voltage is routed through circuits 1337 (VT/YE) and 1335 (YE/WH) to the LH and RH headlamps, respectively.







This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- High beam relay
- HID relay
- Headlamp switch
- Multifunction switch
- BEC
- SJB

F1-F2:

F3-F6:

F6-F10:

F11-F13:

F14-F17:

F18-F21: