Lamps/Lighting - Interior
LAMPS/LIGHTING - INTERIORDESCRIPTION
The interior lighting system for this model includes incandescent lighting on two separate circuits: the dome/courtesy lamp circuit and the panel lamps dimmer circuit. The lamps on the dome/courtesy circuit include:
- Courtesy Lamps (1) - Standard courtesy lamps are located under the right and left ends of the instrument panel, and are controlled by the courtesy lamp circuit.
- Glove Box Lamp (7) - A standard glove box lamp with an integral plunger-actuated switch is located just inboard of the glove box latch striker on the instrument panel upper glove box opening and illuminates whenever the glove box is opened.
- Liftgate Lamp (6) - A standard liftgate lamp is located in the lower left corner of the liftgate trim panel and is activated automatically whenever the liftgate is opened to illuminate the rear cargo area of the vehicle.
- Front Dome/Reading Lamps (3) - Front seat driver side and passenger side courtesy/reading lamps located on the headliner above each front door opening are controlled by both the courtesy lamp circuit and independent lens-actuated switches.
- Second Row Dome/Reading Lamps (4) - The second row seat dome/reading lamps are controlled by both the courtesy lamp circuit and independent lens-actuated switches. These lamps are integral to the grab handles located on the headliner above each rear door opening adjacent to each outboard rear seating position.
- Third Row Dome/Reading Lamp (5) - The third row seat dome/reading lamp is controlled by both the courtesy lamp circuit and an independent lens-actuated switch. This lamp is centrally located in the headliner above the third row seat and also serves as a cargo area lamp when the third row seats are folded flat.
- Vanity Lamps (2) - Optional single-intensity vanity lamps are located above a covered mirror on both the right and left sun visors, and are controlled by an integral vanity mirror cover-actuated switch on the courtesy lamp circuit.
Most controls on the instrument panel and elsewhere in the interior of the vehicle are illuminated by the panel lamps dimmer circuit for night visibility. All have either miniature incandescent bulbs or Light-Emitting Diode (LED) units that are soldered to internal circuit boards and are not serviceable.
Other components of the interior lighting system for this model include:
- Door Ajar Switches - A door ajar switch is integral to the door latch mechanism of each front and rear door.
- Instrument Cluster - The Electromechanical Instrument Cluster (EMIC) is also known as the Cab Control Node (CCN) in this vehicle. The EMIC/CCN is located in the instrument panel above the steering column opening, directly in front of the driver.
- Flip-Up Glass Ajar Switch - A flip-up glass ajar switch is integral to the flip-up glass latch mechanism on the top of the lower flip-up glass opening in the liftgate inner panel.
- Left Multi-Function Switch - The left multi-function switch is located on the top of the steering column, just below the steering wheel. The left multi-function switch includes a control stalk with a control knob and a control sleeve. These controls are dedicated to providing almost all of the driver controls for both the exterior and interior lighting systems.
- Liftgate Ajar Switch - A liftgate ajar switch is integral to the latch mechanism of the liftgate.
Hard wired circuitry connects the interior lighting system components to the electrical system of the vehicle. These hard wired circuits are integral to several wire harnesses, which are routed throughout the vehicle and retained by many different methods. These circuits may be connected to each other, to the vehicle electrical system and to the interior lighting components through the use of a combination of soldered splices, splice block connectors, and many different types of wire harness terminal connectors and insulators. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, further details on wire harness routing and retention, as well as pin-out and location views for the various wire harness connectors, splices and grounds.
OPERATION
The interior lighting systems can be divided into two general classifications based upon the circuit that controls their operation: The courtesy lamp circuit, or the panel lamps dimmer circuit. The hard wired circuits and components of the interior lighting systems may be diagnosed and tested using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods may not prove conclusive in the diagnosis of the Electromechanical Instrument Cluster (EMIC), or the Controller Area Network (CAN) data bus. The most reliable, efficient, and accurate means to diagnose the EMIC, the CAN data bus, or the electronic bus message inputs and outputs related to the various interior lighting systems requires the use of a diagnostic scan tool.
COURTESY LAMP CIRCUIT
The courtesy lamp circuit includes the courtesy lamps located under each outboard end of the instrument panel, the dome or map/reading lamps located on the inner roof side rails adjacent to the front and second row outboard seating positions, the cargo or map/reading lamp located in the center of the headliner over the third row seating positions, the liftgate lamp located near the lower left corner of the liftgate trim panel, the glove box lamp in the top of the glove box opening in the instrument panel, and the vanity lamps located in the sun visors. The lamps in the courtesy lamp circuit are provided with battery voltage at all times from a fuse in the Junction Block (JB). The EMIC controls the ground path for these lamps using an internal driver through a courtesy lamp driver circuit based upon hard wired inputs from the door ajar switches, the flip-up glass ajar switch, and the liftgate ajar switch. The EMIC also uses electronic left multi-function switch and ignition switch status message inputs received from the Steering Control Module (SCM) over the CAN data bus.
After all of the ajar switch inputs to the EMIC transition to open, the EMIC will keep the courtesy lamps illuminated for about 30 seconds, then fade the lamps to off (theater dimming) over about three seconds. The EMIC also provides courtesy lamp operation based upon the left multi-function switch status input from the SCM, and provides an illuminated entry feature in response to certain electronic message inputs received from the Sentry Key REmote Entry Module (SKREEM) and the Occupant Restraint Controller (ORC) over the CAN data bus. A courtesy lamp defeat feature based upon the left multi-function switch status input from the SCM will cause the EMIC to override normal courtesy lamp operation based upon any ajar switch inputs.
For those lamps on the courtesy lamp circuit with independent switching, such as the standard or optional map/ reading lamps, the vanity lamps and the glove box lamp the EMIC provides a ground path to the switches using another internal driver through a courtesy lamp load shed circuit. The EMIC provides a battery saver (load shedding) feature for all courtesy lamps, which will automatically turn these lamps off if they are left on for more than about eight minutes with the ignition switch in the Off position.
PANEL LAMPS DIMMER CIRCUIT
The panel lamps dimmer circuit actually includes several circuits. These circuits control the illumination and dimming level of the upper and lower instrument panel switch pods, the front and rear heater-air conditioner controls, the four-wheel drive selector switch and the transmission gearshift lever assembly. All lamps in the panel lamps dimmer circuits are provided a path to ground at all times through a hard wired ground circuit. These lamps are illuminated by a 12-volt Pulse Width Modulated (PWM) output through several individual panel lamps dimmer circuits.
This shared PWM output synchronizes the selected illumination intensity level of all of the lamps in the panel lamps dimmer circuits. The EMIC uses a hard wired input from the park lamp relay and electronic dimming level message inputs from the SCM over the CAN data bus based upon the dimming level selection of the control sleeve on the left multi-function switch control stalk.
The EMIC and the radio use the dimming level messages from the SCM to control the illumination intensity of their own Vacuum Fluorescent Display (VFD) units and controls. In addition, when the control sleeve of the left multifunction switch is moved to the Parade/Funeral Mode detent position, all of the VFD units are illuminated at their full intensity levels for increased visibility when the vehicle is driven during daylight hours with the exterior lights turned On. The Parade/Funeral mode has no effect on the illumination intensity of incandescent panel lamps.