Description
DESCRIPTION
The exterior lighting system for this vehicle includes the following exterior lamp units:
- Center High Mounted Stop Lamp (2) - A standard equipment Center High Mounted Stop Lamp (CHMSL) is centered on the cab roof header panel just above the glass opening at the rear of the cab. An optional CHMSL also incorporates two integral cargo lamps, one located at each outboard side of the CHMSL.
- Front Fog Lamps (5) - Vehicles equipped with this option have a fog lamp unit mounted near each outboard end of the front bumper support, behind the lower portion of the front fascia.
- Front Lamp Units (1) - A standard equipment front lamp unit is mounted to the front of each front fender panel on either side of the grille opening.
- License Plate Lamp (4) - A standard equipment rear license plate lamp unit is mounted to each outboard vertical surface of the license plate tub formation in the center of the rear bumper.
- Rear Lamp Units (3) - A standard equipment rear lamp unit is mounted to the rear of each quarter panel on either side of the tailgate opening.
These exterior lighting lamp units and their controls are combined to provide the following exterior lighting features:
- Automatic Headlamps - Vehicles with the automatic headlamps option are equipped with a unique headlamp switch that includes an A (Automatic) position and have a sun load sensor located on the top of the instrument panel to sense ambient light levels. When the A position of the headlamp switch is selected while the engine is running, the headlamps are turned ON and OFF automatically as ambient light levels dictate.
- Backup Lamps - The backup (or reverse) lamps include a bulb, reflector and lens that are integral to each rear lamp unit.
- Brake Lamps - The brake (or stop) lamps include a bulb, reflector and lens that are integral to each rear lamp unit, and the CHMSL bulb and lens.
- Daytime Running Lamps - Vehicles manufactured for sale in Canada illuminate the high beam filament of the headlamp bulb in each front lamp unit to serve as the Daytime Running Lamps (DRL). Fleet vehicles manufactured for sale in the United States illuminate the low beam filament of the headlamp bulb in each front lamp unit to serve as the DRL.
- Exterior Lamp Fail-Safe Operation - The ElectroMechanical Instrument Cluster (EMIC) (also known as the Cab Compartment Node/CCN) and the Front Control Module (FCM) provide a fail-safe feature which will automatically turn ON the low beam headlamps and all park lamps when the ignition switch is in the ON position and there is no detected input from the headlamp switch, or when there is no communication over the Controller Area Network (CAN) data bus.
- Exterior Lamp Load Shedding - The FCM provides a battery saver feature which will automatically turn OFF all exterior lamps that remain ON with the ignition switch in the LOCK position after a timed interval of about eight minutes.
- Front Fog Lamps - The optional front fog lamps include the bulb, reflector and lens of each adjustable front fog lamp unit.
- Hazard Warning Lamps - The hazard warning lamps include the bulbs, reflectors and lenses of each lamp in the right and left, front and rear turn signal circuits.
- Headlamp Delay - The low or high beam headlamps remain illuminated for a dealer-programmable delay period of 30, 60 or 90 seconds when the headlamp switch is turned to the OFF position after the ignition switch has been turned to the OFF position.
- Headlamps - The headlamps include a single, dual filament halogen bulb, an adjustable reflector and a clear lens integral to each front lamp unit.
- Optical Horn - Also known as flash-to-pass, the beam selection function of the multi-function switch control stalk has a momentary intermediate position that allows the headlamp high beams to be flashed momentarily, without changing the headlamp beam selection.
- Park Lamps - The park lamps include the park and side marker bulbs, reflectors and lenses integral to each front and rear lamp unit as well as the bulbs and lenses of the rear license plate lamps.
- Turn Signal Lamps - The turn signal lamps include the turn signal bulbs, reflectors and lenses that are integral to the right and left front and rear lamp units.
Other components of the exterior lighting system for this vehicle include:
- Backup Lamp Switch - A plunger-type backup lamp switch is installed through the transmission housing of vehicles equipped with a manual transmission and is actuated by the shifter mechanism within the transmission when REVERSE gear is selected. On vehicles with an optional automatic transmission, depending upon the transmission type, either a stand-alone Transmission Range Sensor (TRS), or a TRS that is integral to the solenoid pack on the valve body performs the backup lamp switch function.
- Brake Lamp Switch - A plunger-type brake lamp switch is located on the steering column support bracket under the instrument panel and is actuated by the brake pedal arm when the brake pedal is depressed.
- Clockspring - The clockspring includes an integral turn signal cancel cam, which provides automatic turn signal cancellation as the steering wheel is rotated back to its centered position following a vehicle turning maneuver. The clockspring is located near the top of the steering column, directly beneath the steering wheel. Description.
- Front Control Module - The Front Control Module (FCM) is integral to the Integrated Power Module (IPM). The FCM/IPM is located in the engine compartment, near the battery and the Power Distribution Center (PDC). Description.
- Front Fog Lamp Relay - Vehicles equipped with optional front fog lamps have a front fog lamp relay located in the Power Distribution Center (PDC).
- Headlamp Switch - A headlamp switch is located on the left side of the instrument panel, below and outboard of the steering column. The headlamp switch includes a rotary knob to turn the park lamps and headlamps ON or OFF and, on vehicles so equipped, a push button switch for selecting the optional cargo lamps. The rotary knob is pushed inward for selecting the optional front fog lamps on vehicles so equipped. The headlamp switch also features a vertical thumbwheel for selecting the panel lamps dimming level, a PARADE mode to illuminate all Vacuum Fluorescent Display (VFD) units at full brightness for visibility when driving in daylight with the exterior lighting turned ON, and for interior lighting control.
- Instrument Cluster - The ElectroMechanical Instrument Cluster (EMIC) is also known as the Cab Compartment 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. Description.
- Multi-Function Switch - The multi-function switch is located on the steering column, just below the steering wheel. A control stalk that extends from the left side of the switch is used to select the turn signal lamps (right or left) and to select the headlamp beam (low, high or optical horn). A push button that extends from the top of the switch is used to select the hazard warning lamps.
- Park Brake Switch - A park brake switch is located on the park brake pedal mechanism on the cowl side inner panel below the instrument panel, to the left of the steering column.
- Park Lamp Relay - A park lamp relay is located in the Power Distribution Center (PDC) of all vehicles.
- Trailer Tow Relays - Vehicles with a factory-installed trailer towing package have two trailer tow relays installed in the Power Distribution Center (PDC) in the engine compartment, one for the trailer right turn and brake lamps and the other for the trailer left turn and brake lamps.
- Trailer Tow Wiring - All vehicles have a factory-installed 4-way trailer tow wire harness and connector as standard equipment. Vehicles with a factory-installed trailer towing package have a trailer tow wire harness and a heavy duty 7-way trailer tow connector installed on a bracket on the trailer hitch receiver platform. This package also includes an electric trailer brake wiring provision that terminates at a connector located on top of the large body harness connection under the instrument panel to the left of the brake pedal, as well as an electric trailer brake pigtail harness and an instruction card that are stored in the glove box when the vehicle is shipped from the factory.
Hard wired circuitry connects the exterior 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 exterior 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.