Lamps and Lighting
Lamps and Lighting
Description
Lamp Systems
Lighting circuits are protected by fuses and other circuits are high side drivers. High side drivers are computer controlled solid state switching circuits within the totally integrated power module. If there were a short in the lighting circuit that was HSD operated, The TIPM would sense the short and protect the circuit from being damaged by making several attempts to actuate, then shut off. The tail lamps, parking lamps, headlamps stop lamps, turn signal lamps, fog lamps (if equipped), side repeater lamps are all on HSD within the TIPM. The back up lamps are fused and relay controlled through the TIPM. The center high mounted stop lamp is fused battery.
The headlamp switch and multifunction switch control the exterior lighting by providing inputs to the TIPM over the bus through the cabin compartment node. The CCN in turn sends a controller area network bus message to the TIPM to enable the necessary drivers to set the required illumination.
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.
Test fuses in the TIPM to be sure there they are not damaged or blown. Using the diagnostic tool, actuate the exterior lighting and proceed with the appropriate diagnostics.
Automatic Headlamp System
The automatic headlamp system turns the instrumentation and exterior illumination lamps ON when the ambient light levels are night and the engine is running, and OFF when light levels are day.
Daytime Running Lamps
Operating the high beam headlamps at reduced power provides daytime running lamps, which are required on all new Canadian vehicles. Daytime running lamps are functional when the engine is running and the gear selector is in any other position than in park.
Headlamps On With Windshield Wipers
For 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, the engine running 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 TIPM will determine if the instrumentation and exterior illumination lamps should remain ON base upon the current ambient light level.
Headlamp System
The operation of the exterior lighting is controlled by the TIPM. The CCN determines the lighting configuration as a result of the inputs from the ignition switch, headlamp switch and multifunction switch, brake switch, switch bank and ambient light sensor. A CAN-I HS bus message is transmitted from the CCN to the TIPM to enable the necessary drivers to set the illumination configuration. There is hard wiring connected between the headlamp switch and the CCN. The first wire contains information regarding the position of the headlamp switch. The second wire contains information regarding the position of the dimmer switch. The third wire is a dedicated signal return wire. The fourth wire provides power to the front fog lamp indicator.
Headlamp Time Delay System
The TIPM controls the headlamp delay feature using inputs for the Ignition key position, headlamp switch position, and a configured time setting. Turning off the headlamps after turning off the ignition will enable this feature to keep the headlamps on for a programmable amount of time.
Operation
Automatic Headlamp System
Automatic headlamps are controlled by the TIPM. With the headlamp switch in the AUTO position, the TIPM will control the headlamp, parking, side marker, tail and instrumentation lamps based on ambient light levels. Ambient light levels are measured by the heating, ventilation and air conditioning module and communicated to the CCN as a voltage level in a CAN I-HS message. The CCN then compares the voltage level to a threshold and communicates an automatic headlamp ON/Off message to the TIPM in a CAN I-HS message. The TIPM turns on the exterior lights based upon the headlamp switch setting, the CCN automatic headlamp request and the engine running state. 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.
Daytime Running Lamps
Power is reduced using pulse width modulation to the high beams, where by the power is switched on and off rapidly instead of remaining on continuously. The duration and interval of the power pulses is programmed into the TIPM. Daytime running lamps are functional when 450 RPMs are reached.
Headlamp System
The headlamp system will default to the headlamps ON mode when the ignition switch is ON and CAN I-HS communications has failed between the CCN and the TIPM. The system will return to normal operation when the open or short is repaired. A fault will be reported by the CCN hen a failure occurs on the dimmer or headlamp switch input. Should any communication issues occur between the CCN and the TIPM, the TIPM will log communication faults against the CCN.
If the exterior lamps are ON and the headlamp switch is in any position other than OFF or AUTO and with the ignition switch OFF (LOCK), the headlamps, fog lamps and park/tail lamps will be turned off by the TIPM after 8 minutes. This will only occur if the headlamp switch is turned to the off position prior to the 8 minute time out. This feature prevents the vehicle battery from being discharged when the vehicle lights have been left ON. Park lamp load shedding is disabled in some markets.
Headlamp Time Delay System
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 TIPM will allow the headlamps to remain ON for 90 seconds before they automatically turn off. Refer to the owner manual for more information. When the headlamp switch is in the AUTO position, the headlamp time delay system will function when the ignition switch is placed in any position other than run/start.
If the headlamp switch is in the auto headlamp position, the headlamps are ON due to the night signal from the CMTC and the ignition is in any position other than run/start, the TIPM shall enter a 90 second auto headlamps time delay mode. If the key is in the ignition during the headlamp time delay mode, then both the headlamps and park lamps, including panel dimming, will be ON. If the Fob Integrated Key is not in the ignition, then only the headlamps will be ON. The TIPIM will allow the headlamps to remain ON for 90 seconds before they automatically turn OFF. Refer to the owners manual for more information.
Optical Horn/High Beams
When the multifunction switch is pulled to the first detent signal, the headlamps are on, key in the ignition, the CCN shall send a message via PCI bus to the TIPM to turn on the headlamps drivers to illuminate all four filaments. When the multifunction switch is pulled to the second detent signal and the headlamps are on, the CCN shall send a message via PCI bus to the TIPM to turn on the headlamps drivers. The high beams are illuminated and the low beams and fog lamps are extinguished. If the headlamps were in the high beam configuration when power was removed from the headlamps, the headlamps will be configured as low beam the next time they are activated. The time overlap when both the high beams and low beams are simultaneously on is limited to 0.2 seconds. The low beams will drop out if the optical horn is activated for longer than 0.2 seconds. The CCN reads the switch and the messages are sent to the TIPM.