Lighting and Horns: Description and Operation
GENERAL INFORMATIONLH vehicles use lighting on the interior and exterior of the vehicle for illuminating and indicating purposes. Lighting circuits are protected by fuses or circuit breakers. Lighting circuits require an overload protected power source, on/off device, lamps and body ground to operate properly. Plastic lamp sockets require a wire in the harness to supply body ground to the lamp socket. Lamp sockets that are exposed to moisture should be coated with Mopar� Multi purpose Grease or equivalent to avoid corrosion. if a socket has become corroded, clean socket and bulb base with abrasive fiber sanding pad or metallic bristle brush. Replace sockets and bulbs that are deformed from corrosion that could prevent a continuous body ground.
Wire connectors can make intermittent contact or become corroded. Before coupling wire connectors, inspect the terminals inside the connector. Male terminals should not be bent or disengaged from the insulator. Female terminals should not be sprung open or disengaged from the insulator. Bent and sprung terminals can be repaired using needle nose pliers and pick tool. Corroded terminals appear chalky or green. Corroded terminals should be replaced to avoid recurrence of the problem symptoms. Wire connector terminals should be coated with Mopar� Multi purpose Grease or equivalent to avoid corrosion.
Begin electrical system failure diagnosis by testing related fuses and circuit breakers in the fuse block and engine compartment. Verify that bulbs are in good condition and test continuity of the circuit ground.
Automatic Headlamp System
The Automatic Headlamp system turns the instrumentation and exterior Illumination lamps ON when the ambient light levels are low and OFF when light levels are high. Automatic headlamps are controlled by the Body Control Module (BCM). With the headlamp switch in the AUTO position, the BCM will control the headlamp, parking, side marker, tail and instrumentation lamps based on ambient light levels. Ambient light levels are monitored by the BCM using the automatic temperature control system Sun load Sensor, located on the top of the instrument panel cover. Ambient light readings are averaged to limit cycling the lamps ON and OFF when passing through areas with varying light levels. The automatic headlamps will only function when the engine is running. When the headlamp switch is in the AUTO position (Automatic mode), the Headlamp Time Delay system will function when the ignition is switched OFF
Courtesy Lamps
The Body Control Module (BCM) illuminates the courtesy lamps whenever a door is opened. When the last door is closed, the BCM "fades-to-OFF" the courtesy lamps in five seconds. If a door is left ajar, the courtesy lamps remain on for a maximum of one hour when ignition switch is OFF. After one hour, the BCM "fades-to-OFF" the courtesy lamps.
Daytime Running Lamps - Canada Only
The daytime running lamps are controlled by the Daytime Running Lamp Module (DRL Module). The DRL module is attach to the Junction Block. The Junction Block is located on the left side of the instrument panel. The DRL allows the high beam headlamps to illuminate at reduced power when the ignition switch is in the run position with the high and low beam headlamp switches in the OFF position. The Park Brake must be released and the Brake Fluid Level switch must be in the open position to allow the headlamps to operate in DRL mode. The daytime running lamps will go out when the headlamp switch is turned ON. The passing light feature will flash bright high beams while the daytime running lamps are activated.
Headlamps On With Windshield Wipers
Vehicles equipped with the Automatic Headlamp System the instrumentation and exterior illumination lamps will be turned ON when the headlamp switch is in the AUTO position and the windshield wipers have been in the intermittent, low or high mode of operation for more than ten seconds. When the windshield wipers are turned OFF the Body Control Module will determine if the instrumentation and exterior illumination lamps should remain ON base upon the current ambient light level.
Headlamp System
The headlamp system is controlled completely by the Body Control Module (BCM). The BCM controls the Park lamps, Headlamps, and Front Fog Lamps using relays located in the Junction Block. Three wires are connected between the headlamp switch and the BCM. The first wire contains information regarding the position of the headlamp switch (Off, Automatic Headlamps, Automatic Headlamp switch fog, Park with Fog, Head, or Head with Fog Lamps). The second wire contains information regarding the position of the dimmer switch (Dome Lamp, Daytime Brightness, or Dimming Level). The third wire is a dedicated signal return (ground) wire.
The headlamp system will default to headlamps ON position when ignition switch is ON when an open or short circuit failure occurs on the headlamp switch input. The system will return to normal operation when the open or short is repaired. A fault will be reported by the BCM when a failure occurs on the dimmer or headlamp switch input.
The dimmer system will default to Daytime Brightness when an open or a short occurs on the dimmer switch input.
The BCM will turn OFF the exterior lamps if they are left ON with the ignition switch OFF for more than ten minutes. This feature prevents the vehicle battery from being discharged when the vehicle lights have been left ON.
Headlamp Time Delay System
The Headlamp time Delay system is controlled by the Body Control Module (BCM) through the headlamp relay. The headlamp time delay system is activated by turning the headlamps ON (high or low beam) while the engine is running, turning the ignition switch OFF and then turning the headlamp switch OFF within 45 seconds. The system will not activate if more than 45 seconds elapse between ignition switch OFF and headlamp switch OFF. The BCM will allow the headlamps to remain ON for 90 seconds before they automatically turn off. Refer to the Owner's Manual for more information.
Illuminated Entry
The Illuminated Entry System is available on vehicles equipped with the Remote Keyless Entry system. The Illuminated Entry System turns ON the courtesy lamps when the remote keyless entry system is activated. The Remote Keyless Entry Module and the Body Control Module (BCM) are used to control the system. Courtesy lamps will turn on for 30 seconds (± 1 second) and "fade-to-OFF" over a five second period.
The Illuminated Entry System also turns ON the courtesy lamps when a door is opened. The courtesy lamps will remain ON while the door is open, then "fade-to-OFF" 30 seconds (1 second) after the last door is closed.
The courtesy and ignition ley halo lamps will "fade-to-OFF" immediately when the ignition is switched to ON.
The Illuminated Entry System cannot be activated during the 30 second ( ±1 second) period after the ignition switch is turned OFF except by using the RKE transmitter. If a door is opened and closed during this 30 second period, the system will function as previously described.
The courtesy lamps will fade to OFF immediately, if the Remote Keyless Entry lock function is actuated with all doors closed.