Principles of Operation

WARNING: This page is about a different car, the 2008 Mercury Sable, 2008 Ford Taurus X, and 2008 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: The time out for the battery saver relay and the accessory delay relay (both are controlled by the SJB) is 1 minute if the vehicle has less than 80 km (50 miles). Once the vehicle passes the approximate mileage threshold of 80 km (50 miles), the time out for both relays will be the normal 10 minute time out, as described by the Owner's Literature. For the battery saver relay, refer to INTERIOR LIGHTING article. For the accessory delay relay, refer to GLASS, FRAMES AND MECHANISMS article.

NOTE: The smart junction box (SJB) is also known as the generic electronic module (GEM).

The SJB is a multifunction module that controls many of the vehicle systems. Most of the SJB functions utilize hardwired inputs and/or outputs. The SJB controls the following hardwired functions, using the corresponding inputs and outputs:

Function	Input(s)	Output(s)
Accessory delay	Master power window switch Power sliding roof switch Audio control module (ACM)	Accessory delay relay
Autolamps (if equipped)	Headlamp switch Ambient light sensor	Exterior lamps
Battery saver	Internal to SJB	Battery saver relay
Daytime running lamps (if equipped)	Ignition switch status Parking brake status	Low beam headlamps
Luggage compartment lid release	Luggage compartment lid release switch	Luggage compartment lid release relay
Fog lamps (if equipped)	Headlamp switch	Fog lamp relay
Headlamps (low beam)	Headlamp switch	Low beam headlamps
Headlamps (high beam and flash-to-pass)	Headlamp switch Multifunction switch	High beam relay
Heated rear window	Heated rear window switch	Heated rear window relay
Horn	Horn switch	Horn relay
Parking lamps	Headlamp switch	Parking lamps relay
Power door locks	Driver door lock control switch Passenger door lock control switch	Door lock/unlock relays
Remote keyless entry (RKE) system	Keyless entry keypad RKE transmitter (part of the integrated keyhead transmitter [IKT] key)	Power door locks Parking lamps Horn
Stoplamps	Stoplamp switch	Stoplamps
Turn signal/hazard lamps	Multifunction switch Hazard lamps switch	Turn signal/hazard lamps

In addition, the SJB is involved in other vehicle systems through communication over the medium speed controller area network (MS-CAN). For a detailed list of SJB network inputs and outputs, refer to MODULE COMMUNICATIONS NETWORK article, Principles of Operation .

Some SJB parameters are programmable. Two types of programmable parameters are available: vehicle configuration and customer preference. Refer to MODULE CONFIGURATION article.