Normal Operation
WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. However, it is still accessible from the selected car via links, so may be relevant.
The Smart Junction Box (SJB) sends a voltage signal to the multifunction switch for the high beam and flash-to-pass requests. When the multifunction switch is placed in the FLASH-TO-PASS or HIGH BEAM position, the voltage signal is routed to ground. When the SJB detects a request for flash-to-pass or high beams (when the low beams are on), the SJB energizes the high beam relay (integrated into the SJB), which routes voltage to the headlamps.
NOTE:
For Milan headlamps, if the SJB high beam output circuit is supplied voltage when the headlamps are not on, the headlamps do not illuminate. The SJB high beam output circuit only supplies voltage to activate the high beam shutters within the headlamp assemblies. The low beams must be on for light to illuminate from the headlamps.
- DTC B1510 (Flash To Pass Switch Circuit Short to Ground) - an on-demand DTC that sets when the SJB detects the flash-to-pass request input circuit is short to ground.
- DTC B2A23 (High Beam Input Circuit Short to Ground) - an on-demand DTC that sets when the SJB detects a short to ground on the high beam request input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Multifunction switch
- SJB