Exterior lighting consists of the following lamps:

The headlamps consist of two interchangeable single filament bulbs or 2 high intensity discharge (HID) arc tubes and ballast on each side of the vehicle which provide high and low beams. The lower bulb in the headlamp is the high beam and the upper bulb is the low beam.

The headlamps may be turned on in three different ways:

With the headlamp switch in the ON position, the headlamp switch signal circuit is grounded through the headlamp switch to G200. In response to this input, the dash integration module (DIM) provides ground to either the LO BEAM relay control circuit or the HI BEAM relay control circuit. The position of the dimmer switch determines which relay coil has ground. The DIM supplies battery positive voltage to the relay coil circuits, if the headlamps are necessary. The underhood fuse block supplies battery positive voltage to both relay switch circuits. When the low beam relay coil is energized, current flows through the LT LOW BEAM fuse and the RT LOW BEAM fuse to the low beam headlamps. The low beam headlamps have ground at G104. When the HI BEAM relay coil is energized, current flows through the LT HI BEAM fuse and the RT HI BEAM fuse to the high beam headlamps. The high beam headlamps also have ground at G104. When the headlamp dimmer switch lever is pulled toward the driver, the Flash-To-Pass switch closes. This grounds the DIM Flash-To-Pass input. In response to this input, the DIM energizes the high beam relay. Both high beams remain on until the driver releases the switch handle. If the low beam headlamps were on during Flash-To-Pass operation, the low beams remain on. The headlights may be switched to high beam with the opposite movement of the dimmer switch lever. All CTSs exported to Norway, Sweden, Finland, or Israel will operate so that the low beam headlamps will also remain illuminated when the dimmer switch is in the high beam position. With the dimmer switch in the high beam position the DIM sends a class 2 message to the instrument panel cluster (IPC) requesting the IPC to illuminate the high beam indicator. If the headlamp switch is left in the ON position, the inadvertent power control feature will turn off the headlights 10 minutes after the ignition switch is turned to the OFF position. If the driver places the headlight switch in the ON position after the ignition switch has been turned OFF, or if the ignition switch is in the ACCY position, the headlights will remain on until turned off or the battery runs dead.

During automatic lamp control (ALC) the headlamps will be in low beam operation during low light conditions. A HEADLAMPS SUGGESTED message will appear on the driver information center (DIC) when the headlamps and park lamps are off due to all exterior lighting controls being inactive when night time conditions are sensed. The auto position of the headlamp switch is supplied a 5 volt reference from the dash integration module (DIM). With the headlamp switch in the auto position, the 5 volt reference is pulled low and enables the auto lamp feature. When the ignition is on the DIM will automatically turn the headlamps on or off according to the day/night status of the ambient light sensor.

The headlamps on with wipers feature operates when the following conditions are true:

When the headlamps on with wipers feature is active the DIC will display the HEADLAMPS SUGGESTED message.

The HID system is made up of the ballast and arc tube. The headlamp ballast receives the headlamp low beam supply voltage, which would normally be used to directly supply the low beam headlamp. Each ballast has a separate ground. The HID headlamp operation consist of three states. The startup or strike state, run up state, and steady state. When the headlamp switch is turn to the ON position the ballast may draw up to 20 amps to being the strike state. The ballast will provide multiple high voltage pulses to the arc tube in order to start the bulb. The voltage provided by the ballast during the startup state ranges from -600 volts to +600 volts. Once an arc is established, the ballast will provide a higher then steady state voltage to the arc tube in order to keep the bulb illuminated. This is called the run up state, on a cold bulb this state could last as long as 41 seconds. On a hot bulb the run up state may last as long as 15 seconds. Steady state operation begins when the bulb reaches the 35 watt power level. The ballast provides the bulb with a minimum of 55 volts during steady state operation.

For proper operation of the HID system ensure the battery and the harness are capable of supplying up to 20 amps of current per ballast, with less than 2 volts of system loss or voltage drop. Each ballast requires up to 20 amps in order to ensure normal startup and run up of the lamp.

The range of white light that is acceptable is broad when compared to halogens. Therefore, some variation in headlight coloring between the right and left headlamp will be normal. Replace the arc tube only if the arc tube is determined to be at the bulb failure stage.

The DIM monitors the vehicle's system voltage while in the RUN power mode. When the system voltage drops below 8.9 volts, the following will occur:

STAGE 1: If the low beam headlamps are on, whether manually or automatically the DIM will turn ON the high beam headlamps by activating Flash to Pass output control and turn OFF the low beam headlamps

When the system voltage drops below 8.5 volts, the following will occur:

If during the same ignition cycle, the DIM enters either STAGE 1 or STAGE 2 operations noted above, then determines that the system voltage has risen, the following will occur:

The Automatic Headlamp Leveling systems consist of the following components:

The automatic headlamp leveling system automatically maintains the vertical alignment of the headlamps when the vehicle load and driving conditions change. The right and left headlamp leveling controllers share the inputs from the front and rear axle position sensors to determine vehicle pitch. The axle sensors send an output to the headlamp leveling controllers as the vehicle suspension compresses and rebounds. The controllers calculate the difference in vehicle pitch and send a command to the HID ballast. The ballast then drive the headlamp leveling actuators to the position commanded by the controllers. The headlamp leveling system also monitors the performance of the HID bulb and ballast. When the headlamp switch is placed in the ON position the headlamps will go down, and then back up to the center position.

The daytime running lamps (DRL) will illuminate the right and left front turn signal bulbs continuously. The DRLs will operate when the following conditions are met:

1. The ignition is in the RUN or CRANK position
2. The shift lever is out of the PARK position for vehicles equipped with automatic transmissions or the parking brake is released for vehicles with manual transmissions.
3. The high and low beam headlamps are OFF.

When conditions for DRL operation exist, the engine control module (ECM) sends a class 2 message to the dash integration module (DIM), on vehicles equipped with automatic transmissions indicating the transmission is out of the PARK position. The instrument panel cluster sends a class 2 message to the dash integration module (DIM), on vehicles that are equipped with manual transmissions that the parking brake is release. The dash integration module (DIM) sends a signal to the turn/hazard/DRL module by grounding the DRL signal circuit of the turn/hazard/DRL module. When the turn/hazard/DRL module receives this signal the module supplies continuous battery voltage to the right and left front turn signal lamps. The turn signal lamps are permanently ground at G104 and therefore illuminate. Turn signal and hazard flasher operation take precedence over DRL operation. For Domestic vehicle only , Daytime Running Lamp (DRL) operation will be disabled if the ambient light sensor indicates NIGHT conditions, the twilight switch is turned OFF and either the front fog lamps or park lamps are turned ON.

The daytime running lamps (DRL) will illuminate the low beam headlamps and the park lamps at normal intensity. The DRLs will operate when the following conditions are met:

When conditions for DRL operation exist, the ECM sends a class 2 message to the dash integration module (DIM), on vehicles equipped with automatic transmissions indicating the transmission is out of the PARK position. The instrument panel cluster sends a class 2 message to the dash integration module (DIM), on vehicles that are equipped with manual transmissions that the parking brake is release. The dash integration module (DIM) will then ground the control circuit of the DRL relay and the park lamp relay. Battery voltage is supplied to the coil and switch side feed circuits of the DRL relay. When the DIM grounds the control circuit of the DRL relay the switch contacts close and battery voltage is supplied to the low beam headlamps. Operation of the park lamps and are the same as described in the park lamp section.

The twilight sentinel provides the occupants adjustable time delay operation of the park lamps and headlamps. The twilight delay is programmable through the Drivers Information Center (DIC) for Driver 1 and Driver 2. Refer to Personalization Description and Operation in Personalization for more Driver 1 and Driver 2 information. The following delay settings are available to Driver 1 and Driver 2 :

The DIC will enable the park/headlamp delay feature under the following conditions:

The delay timer starts once a door is opened. The lights will not turn off until the set time has been completed.

With the ignition switch in the ON or START position, the fog lamps will illuminate when the driver places the front fog lamp switch in the ON position. The Dash Integration Module (DIM) controls the FOG LP relay coil. When the driver turns ON the front fog lamp switch , the switch momentarily grounds the front fog lamp input circuit of the dash integration module (DIM). In response to this input, the DIM grounds the control circuit of the FOG LP relay. The underhood fuse block supplies battery positive voltage to the switch circuit of the front FOG LP relay. Ignition voltage is available to the FOG LP lamp relay coil when the key is in the ON or START position. When the dash integration module (DIM) grounds the control circuit the relay coil energizes, closing the switch contacts. Current then flows from the FOG LP relay switch to both front fog lamps. Both front fog lamps are permanently grounded at G104. The state of the front fog lamps will be retained when the ignition is cycled off and on.

The dash integration module (DIM) will turn ON the park lamps when the fog lamps are ON and send a class 2 message to the instrument panel cluster (IPC) to enable the fog lamp indicator. The front fog lamps will deactivate when either the flash-to-pass or the high beam headlamps are turned on. For vehicles exported to Japan or any European Country except Norway or Sweden the fog lamps remain illuminated with the operation of the high beam headlamps or flash-to-pass. The fog lamps are deactivated in Norway and Sweden when the low or high beam headlamps are turned ON.

Rear fog lamps are required equipment on some export vehicle equipped with RPO T79. The rear fog lamps are located in the rear deck lid lamp assembly. The rear fog lamps will only operate when the ignition in the RUN position and either the front fog lamps or headlamps are turned ON. When the driver turns ON the rear fog lamp switch , the switch momentarily grounds the rear fog lamp input circuit of the dash integration module (DIM). In response to this input, the DIM sends a class 2 message to the rear integration module (RIM). The RIM response to this message by grounding the rear fog lamp relay control circuit. The RIM also sends a class 2 message to the instrument panel module (IPM). The IPM will then illuminate the rear fog lamp indicator. When the rear fog lamp relay control circuit is grounded this energizes the rear fog lamp relay coil causing the switch side contacts to close. Supply voltage from the RR FOG fuse flows through the rear fog lamp relay switch to the rear fog lamps. The rear fog lamps have permanent ground at G402. The rear fog lamps will deactivate if the front fog lamps or headlamps are turned off , if the ignition is out of the RUN position, or if the driver turns the rear fog lamp switch OFF. The rear fog lamps will default to the OFF position upon a key cycle.

The tail, stop, and turn signal functions are performed by the quarter mounted tail lamps. The quarter mounted tail lamp consists of a red lens and incandescent bulbs. The quarter mounted tail lamp wraps around the corner of the vehicle and serves as the rear side marker. The lower portion of the lamp contains reflectors to alert approaching vehicles for nighttime driving safety. The front park and side marker lamps are part of the front headlamp assembly. The park, tail, license and marker lamps are turned on when the headlamp switch is placed in the PARK LAMP or HEADLAMP position or anytime the headlights are requested. The park lamps are also turned on with the front fog lamps. When the ignition switch is in the ON position, the DIM provides battery positive voltage to the controlled positive voltage circuit of the PARK LAMP relay coil. The underhood fuse block supplies battery positive voltage to the switch contacts of the PARK LAMP relay. When the headlamp switch is in the PARK LAMP or the HEADLAMP position, the park lamp switch signal circuit has ground at G200. In response to this signal, the DIM provides ground to the control circuit of the PARK LAMP relay coil, which energizes the relay coil. This closes the relay switch contacts. Current flows from the PARK LAMP relay to the RT PARK fuse, LT PARK fuse and to the LIC/Dimming fuse. From the fuse, the current flows to the park lamps. The front park lamps are grounded at G104 and the tail lamps are grounded at G401 and G402. The LIC/Dimming fuse supplies battery positive voltage to the license lamps, and to the dash integration module (DIM) park lamp input, for interior lamps dimming. The license lamps are grounded at G402. The inadvertent power control feature prevents the park lights from remaining on more than 10 minutes if left on. If the park lights are turned on after the ignition switch has been turned OFF, or is in the ACCY position, they will remain on until turned off or the battery runs dead.

The position lamps are on export vehicles only. European countries require that side position lamps are activated when the vehicle is parked along the side of the road. This feature utilizes the front and rear park and the side marker lamps. The position lamp function operates only when the key is in the OFF position and the gear selector is in the PARK position on vehicles equipped with automatic transmissions or when the parking brake is applied on vehicles equipped with manual transmissions. The position lamp function will operate when the vehicle is in PARK or the parking brake is set and the turn signal switch is placed in the right turn position for the right side position lamps to illuminate or the left turn position for the left side position lamps to illuminate. Battery positive voltage is supplied to the STANDING LP relay coil and switch. Battery positive voltage is supplied through the normally closed relay contacts of the STANDING LP relay switch to each POSN LP relay coil. Battery positive voltage is supplied to each POSN LP relay switch. When the driver places the turn signal lever in the right or left turn position the turn signal switch grounds the respective position lamp relay control circuit. This energizes the relay coil, closing the switch contacts providing battery voltage to the respective park and side marker lamps. When the gear selector is out of the PARK position on vehicles with automatics transmissions or the parking brake is released on vehicles with manual transmissions, the rear integration module (RIM) grounds the STANDING LP relay coil which removes battery positive voltage from each POSN LP relay coil.

The STOP LP SW fuse in the underhood fuse block supplies battery positive voltage to the normally open stop lamp switch. When the driver presses the brake pedal, the switch contacts close. The battery positive voltage flows to the left stop lamp assemblies, to the right stop lamp assemblies, and to the center high mounted stop lamp (CHMSL). The left stop lamp and the CHMSL have ground at G402. The right stop lamp has ground at G401.

The FLASHER fuse in the underhood fuse block supplies battery positive voltage to the turn/hazard flasher module. The turn/hazard flasher module has ground at G200. The turn signal lamps may only be activated with the ignition switch in the ON or START position. The STRG CTRLS fuse in the underhood fuse block supplies battery positive voltage to the turn signal switch. When the turn signal switch is placed in either the left or right position, current flows from the turn signal switch assembly to the turn/hazard flasher module. The turn/hazard flasher module then sends an on-off voltage signal to either the left or right turn signals and the appropriate instrument panel cluster (IPC) indicator. When the IPC receives an input from either of the turn signals it starts to track vehicle mileage. When the IPC has determine that the vehicle has traveled over 1.6 km (1 mile) with one of the turn signals continuously engaged, it shall display the DIC message "Turn Signal On" and request the appropriate chime to notify the driver. The left turn signals have ground at G402. The right turn signals have ground at G401.

The hazard flashers may be activated in any power mode. The hazard flasher switch is permanently grounded through G200. When the driver turns ON the hazard flasher switch the contacts in the switch close, grounding the hazard switch input circuit of the turn/hazard flasher module. The turn/hazard flasher module then supplies battery voltage to all four turn signal lamps and instrument control panel (IPC) in an ON and OFF duty cycle. This illuminates the turn signal lamps in the same manner as explained above. When a THEFT is occurring, the Dash Integration Module (DIM) provides a ground to the turn/hazard flasher module hazard input. This allows the hazard lamps to flash during theft detection.

The repeater lamps are on export vehicles only. Each lamp is located in the front fender. The repeater lamps are used as additional turn signal lamps, and operate as described in the Turn Signal/Hazard Flasher Lamps description. The repeater lamps have ground at G104.

The rear fuse block supplies battery positive voltage through the REVERSE LAMP fuse to the coil and switch terminals of the reverse lamp relay. The dash integration module (DIM) sends a power mode message to the rear integration module (RIM) indicating that the ignition is in the ON position. When the driver of an automatic transmission equipped vehicle places the gear selector in the REVERSE position, the ECM sends a class 2 message to the RIM. The message indicates that the gear selector lever is in the REVERSE position. When the driver places a manual transmission equipped vehicle in reverse the reverse gear position switch mounted on the transmission closes. This provides a ground for the reverse gear position switch signal line, informing the RIM that the transmission is in reverse. For both automatic and manual transmission vehicles the RIM then grounds the control circuit of the reverse lamp relay . This energizes the reverse lamp relay, closing the switch side contacts and providing battery positive voltage to the backup lamp bulbs. The backup lamps are permanently grounded at G402. With both power and ground the backup lamp bulbs illuminate. Once the driver moves the shift lever out of the reverse position a message is send either by class 2 by the ECM or the reverse gear position switch opens causing the RIM to remove the ground from the reverse lamp relay control circuit. This opens the contacts in the relay turning OFF the backup lamps.

When the radio antenna module detects a door UNLOCK command from the keyless entry transmitter, the radio antenna module will send a class 2 message to the dash integration module (DIM). The DIM must have inputs that indicate that the ignition switch is OFF, the park lamps are off, all the doors are closed, and the ambient light sensor is indicating low light conditions. The DIM will then activate the flash to pass relay , park lamp relay and send a class 2 message to the rear integration module (RIM) requesting reverse lamp illumination. The reverse lamp feature may not be available in all countries due to possible export regulations. The DIM will flash the headlamps and park lamps twice, then keep the park and reverse lamps on approximately 20 seconds or until a door is opened. When the radio antenna module detects a door LOCK command from the keyless entry transmitter, The DIM will flash the headlights and park lights once. In daylight conditions, the DIM will activate the park lamp relay only to flash the park lamps twice with a door UNLOCK command and once with a door LOCK command from the keyless entry transmitter.

To provide battery run down protection, the exterior lamps will be deactivated automatically under certain conditions. The Dash Integration Module (DIM) monitors the state of the headlamp switch. If the park or headlamp switch is ON when the ignition switch is placed in either the CRANK or RUN position and then placed in the OFF position, the DIM initiates a 10 minute timer. At the end of the 10 minutes, the DIM will turn off the control power output to the park and headlamp relay coils, deactivating the exterior lamps. This feature will be cancelled if any power mode other than OFF becomes active. The DIM will disable battery run down protection if any of the following conditions exist. The park or headlamp switch is placed in the ON to OFF position, and back to the ON position during battery run down protection. The DIM determined that the park or headlamp switch was not active when the ignition was turned OFF.