The interior lighting system consists of two subsystems: the interior lamps and the demand lamps.
The interior lamp subsystem consists of the approach lamps, footwell lamps, dome lamps, cargo lamp and the sliding door stepwell lamps. The smart junction box (SJB) provides the ground circuit for the dome lamps and the cargo lamp. The remaining interior lamps each have their own separate ground circuit.
The demand lamps subsystem consists of the map lamps, cargo lamp and the LH and RH vanity mirror lamps. Each of these lamps are switched individually and share a common ground circuit.
Power is supplied to the interior lamps through the SJB.
Refer to INTERIOR LIGHTS (Freestar) or INTERIOR LIGHTS (Monterey) for schematic and connector information.
Principles of Operation
When the SJB detects a request for lighting it turns on the interior lamps by supplying power or a ground to specific lamps. The request for lighting can be an open door signal from a door ajar switch, an interior lighting on command from the instrument panel dimmer switch, or an unlock command from a remote keyless entry (RKE) transmitter.
The door ajar switches are hard-wired directly to the SJB. The two front door ajar switches and the liftgate ajar switch are normally closed when the doors are closed. The two rear passenger sliding door ajar switches are normally open when the doors are closed. All door ajar switches receive voltage from the SJB and each has its own ground circuit.
The instrument panel dimmer switch receives a voltage signal from the SJB. The dimmer switch also has a ground circuit return to the SJB. The instrument panel dimmer switch provides variable resistance for backlighting the instrument cluster and a toggle ON/OFF function for the interior lights.
The RKE receiver is contained inside the SJB. When the SJB receives an unlock request from an RKE transmitter it unlocks the doors, and turns on the interior lamps.
All of the interior lights are supplied voltage through the SJB. The following lamps are illuminated by the SJB switching the voltage circuit
- LH approach lamp
- RH approach lamp
- LH rear sliding door stepwell
- RH rear sliding door stepwell
- LH footwell
- RH footwell
The following lamps are illuminated by the SJB controlling ground circuits
- front row dome lamp or overhead console dome lamp (if equipped)
- second row dome lamp
- third row dome lamp
- cargo lamp
The SJB provides the power to the following demand lamps in order to control illumination when in the battery saver mode
- front row map lamps
- second row map lamps
- third row map lamps
- cargo lamp
- RH vanity mirror lamp
- LH vanity mirror lamp
Normal Operation
The interior lighting feature provides interior lighting whenever a door is ajar. The interior lamps are controlled through the SJB. The SJB provides the power and ground for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door step well lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If all interior lamps are inoperative the only common component is the SJB.
The interior lighting feature provides interior lighting whenever a door is ajar. The interior lamps are controlled through the SJB. The SJB provides the power and ground circuits for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door step well lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If only the front dome/map lamps are inoperative, check the power circuit 705 (LG/OG) and depending on vehicle option level either ground 54 (LG/YE) or 1334 (OG/WH).
The interior lighting feature provides interior lighting whenever a door is ajar. The interior lamps are controlled through the SJB. The SJB provides the power and ground circuits for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door step well lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If only the rear dome/map lamps are inoperative, check the power circuit 1458 (VT/WH) and the ground circuit 1334 (OG/WH).
The interior lighting feature provides interior lighting whenever a door is ajar. The interior lamps are controlled through the SJB. The SJB provides the power and ground circuits for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door stepwell lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If the stepwell, footwell or approach lamps are inoperative check the power and ground circuits for each. If all three are inoperative, the concern would be internal to the SJB.
The interior lighting feature provides interior lighting whenever a door is ajar. The interior lamps are controlled through the SJB. The SJB provides the power and ground circuits for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door step well lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If the interior lamps are staying on continuously, the SJB may be receiving an erroneous signal from one of the door ajar switches or the dimmer switch. The liftgate ajar switch and both front door ajar switches are normally closed when the doors are closed and the rear sliding door ajar switches are normally open when the doors are closed.
The interior lighting feature provides interior lighting whenever a door is ajar. The interior lamps are controlled through the SJB. The SJB provides the power and ground circuits for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door step well lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If the interior lamps are not turning on, the SJB may be receiving an erroneous signal from one of the door ajar switches or the dimmer switch. The liftgate ajar switch and both front door ajar switches are normally closed when the doors are closed and the rear sliding door ajar switches are normally open when the doors are closed.
The SJB provides the power circuits for the demand lamps. There are three separate power circuits to the demand lamps. The first, circuit 705 (LG/OG) supplies power to the front dome/map lamps. Next is circuit 1458 (VT/WH) which supplies power for the second row and third row dome/map lamps. Finally circuit 53 (BK/LB) supplies power to the RH and LH vanity mirror lamps. All of the demand lamps share in a common ground, circuit 1205 (BK).
The SJB provides the power circuits for the demand lamps. There are three separate power circuits to the demand lamps. The first, circuit 705 (LG/OG) supplies power to the front dome/map lamps. Next is circuit 1458 (VT/WH) which supplies power for the second row and third row dome/map lamps. Finally circuit 53 (BK/LB) supplies power to the RH and LH vanity mirror lamps. All of the demand lamps share in a common ground, circuit 1205 (BK).
The interior lighting feature provides interior lighting whenever the SJB receives a lamps ON/ doors UNLOCK request from an RKE transmitter or keyless entry keypad. The SJB provides the power and ground circuits for the dome/map lamps and the power circuits for the RH and LH footwell lamps, the RH and LH approach lamps and the RH and LH sliding door step well lamps. The front dome/map lamps are on separate power and ground circuits from the remaining dome/map lamps. Each footwell lamp, approach lamp and sliding door stepwell lamp has its own power circuit from the SJB. If all interior lamps are inoperative the only common component is the SJB.
See also:
• COMPONENT TESTING