Normal Operation
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.
The smart junction box (SJB) sends a pulse-width modulated (PWM) voltage to the dimmable components through circuits VLN04 (VT/GY) and CLN04 (BU/BN) (Fusion, Milan only). Ground for the illumination sources is supplied through circuit GD116 (BK/VT), GD126 (BK/WH), or GD139 (BK/YE).
The window adjust and door lock control switches are only dimmable for MKZ. To diagnose an inoperative window adjust or door lock control switch illumination for Fusion or Milan, go to Pinpoint Test G .
- DTC B2026 (Incandescent Backlighting Output Circuit Failure) - sets when the SJB detects a short to ground on the floor shifter or clock circuit. Only Fusion and Milan set this DTC, as the floor shifter and clock for MKZ receive voltage through the LED illumination circuit. This DTC only sets as a continuous DTC.
- DTC B2027 (LED Backlighting Output Circuit Failure) - sets when a short to ground is detected on circuit VLN04 (VT/GY). This DTC only sets as a continuous DTC.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Illumination source