Dimmable Backlight

WARNING: This page is about a different car, the 2007 Lincoln MKX and 2007 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

When the parking lamps are on, the smart junction box (SJB) monitors the input from the instrument panel dimmer switch. The SJB sends a pulse-width modulated (PWM) voltage to the dimmable components and switches based on input received from the instrument panel dimmer switch.

The SJB also sends a message over the network to the audio unit, the DVD player, the electronic automatic temperature control (EATC) module, and the instrument cluster to indicate the backlight intensity level. If the receiving module receives invalid backlight data from the SJB for 5 seconds or less, the receiving module defaults the backlight to the last setting.

If the receiving module does not receive the backlight status message from the SJB or if the data received is deemed invalid for more than 5 seconds, the receiving module sets DTC U0140 in continuous memory (except the climate control module) and defaults the backlight to full intensity.