High Intensity Discharge (HID) Headlamps
WARNING: This page is about a different car, the 2009 Mercury Milan, 2009 Lincoln MKZ, and 2009 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
Circuits CLF04 (BN/BU) and CLF05 (BU/GN) carry voltage to the LH and RH HID relay coils, respectively. Ground for the HID relay coils is provided through circuit GD121 (BK/YE). Switched voltage for the LH and RH HID relays is provided from the battery junction box (BJB) through circuits SBB26 (YE/RD) and SBB27 (BU/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 GD121 (BK/YE) and GD123 (BK/GY) for the LH and RH headlamps, respectively.
- DTC B1795 (Lamp Headlamp Low-Beam Circuit Open) - is a continuous DTC and sets when the SJB detects an open in the LH or RH low beam output circuit.
- DTC B1797 (Lamp Headlamp Low-Beam Circuit Short To Ground) - is a continuous DTC and sets when the SJB detects a short to ground in the LH or RH low beam output circuit.
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- HID relay
- HID bulb
- Ballast
- Headlamp assembly
- SJB