Exterior Lamps
The exterior lighting consist of the following lamps:
• | Daytime running lamps (DRL) and twilight sentinel |
• | Park, tail, license and marker lamps |
• | Turn signal/cornering lamps |
• | Remote keyless entry (RKE) exterior lamp illumination/perimeter lighting |
Backup Lamps
The B/U LP fuse in the fuse block - instrument panel (I/P) supplies battery
positive voltage to the control and to the switch terminals of the PERIM LP relay.
When the driver selects the REVERSE position, the powertrain control module (PCM)
sends a class 2 message to the remote control door lock receiver (RCDLR). The
message indicates that the gear selector lever is in the REVERSE position. The RCDLR
then energizes the PERIM LP relay and the backup lights illuminate. Current flows
from the reverse lamp relay switch to the backup lamps. The backup lamps have ground
at G400.
Daytime Running Lamps (DRL) and Twilight Sentinel
Twilight sentinel is a driver convenience that controls the exterior lamps in
response to changes to the outside, ambient light level. The ambient light sensor
is a light sensitive transistor that varies its voltage signal to the lamp control
module (LCM) in response to changes to the outside, ambient light level. When the
twilight switch is in ON, the LCM either turns on the daytime running lamps (DRL)
or turns on the low beam headlights, after a 20-second delay depending on whether
daylight or low light conditions are sensed. Any function or condition that turns
on the headlights will cancel the DRL operation. The LCM supplies battery positive
voltage through the DRL resistor, which reduces the voltage to the headlamp low beam
supply voltage circuit. The reduced voltage is then applied through the HDLOBML and
HDLOBMR fuses to the left and right headlamps. The low beam headlamps then illuminate
in the DRL mode. The DRL operate when the ignition switch is in the RUN position,
and the parking brake is not set or the transmission is not in PARK. When these conditions
have been met and the ambient light sensor indicates daytime conditions, the DRL will
illuminate.
Headlamps
The headlamps may be turned ON in 3 different ways:
• | When the headlamp switch is placed in the ON position, for normal operation |
• | With the twilight switch placed in the ON position, for automatic lamp
control (ALC) |
• | With the twilight switch placed in the ON position, with the windshield
wipers ON in daylight conditions, after a 6-second delay--During ALC control
the headlamps will be in daytime running lamp (DRL) operation in daylight conditions,
or low beam operation in low light conditions. |
The lamp control module (LCM) provides battery positive voltage to the signal
circuits of the headlamp switch and headlamp dimmer switch. The circuits include the
headlamp switch headlamps on signal, the headlamp switch flash-to-pass signal and
the headlamp dimmer switch high beam signal. When the headlamp switch is ON, a ground
path is available for the headlamp switch headlamps on signal circuit of the LCM through
the headlamp switch. The LCM provides battery voltage to the headlamp low beam supply
voltage circuit or the headlamp high beam supply voltage circuit, if the headlamps
are necessary. The position of the headlamp dimmer switch determines which circuit
has battery voltage. When the headlamp low beam supply voltage circuit is energized,
current flow goes to both low beam fuses. Current flows to the low beam headlamps.
The headlamps have ground at G105 and at G106. When the headlamp high beam supply
voltage circuit is energized, current flow goes to both high beam fuses. Current flows
to the high beam headlamps. The current flow of the left high beam is from the fuse
to the left high beam lamp. From the lamp, the current flows to G106 with T62 or the
LCM without T62. The current flow of the right high beam is from the fuse to the right
high beam lamp. From the lamp, the current flow is to ground at G105.
Park, Tail and Marker Lamps
The park lamps, including the license lamps and rear door window switch backlighting
are turned ON when the headlamp switch is placed in the PARK , ON position or anytime
the headlights are requested. The PK LP fuse in the fuse block - left underhood
supplies battery positive voltage to the lamp control module (LCM). When the headlamp
switch is in PARK or ON, the park lamp switch signal on circuit of the LCM has a ground
path. The LCM provides battery positive voltage to the park lamp supply voltage circuit.
When the park lamps and/or the tail lamps are ON, the LCM energizes the park lamp
supply voltage circuit. Current flows from the LCM to the LP PK L fuse and to the
LP PK R fuse in the fuse block - instrument panel (I/P). From the fuses, the
current flows to the park lamps. The left park lamps are grounded at G106 and G402.
The right park lamps are grounded at G105 and G400. The LP PK R fuse supplies park
lamp supply voltage to the license lamps and the right rear door window switch backlighting
lamp. The license lamps are grounded at G400. The LP PK L fuse supplies park lamp
supply voltage to the left rear door window switch backlighting lamp.
Remote Keyless Entry (RKE) Exterior Lamp Illumination/Perimeter Lighting
Perimeter lighting provides a personal security feature. The perimeter lighting
feature illuminates the exterior lights on the outside of the vehicle for 15 seconds
when the keyless entry transmitter is used to unlock the doors under night time conditions.
The following lamps illuminate when the perimeter lighting is activated:
When you press the UNLOCK button on the keyless entry transmitter, the remote
control door lock receiver (RCDLR) grounds the headlamp alarm signal circuit to the
lamp control module (LCM). The LCM then provides battery positive voltage to the headlamps
and the park lamps. The RCDLR provides ground for the PERIM LP relay exterior
courtesy lamps relay control circuit. The coil energizes and the switch contacts close
providing supply voltage to the backup lamps.
Turn Signal/Cornering Lamps
The HZDT/SIG fuse in the fuse block - left underhood supplies battery
positive voltage to the turn signal/hazard flasher module and have ground at G202.
The turn signal lamps may only be activated with the ignition switch in the ON or
ACCY position. The T/SIG fuse in the fuse block - left underhood supplies battery
positive voltage to the turn signal/multifunction switch. When the turn signal/multifunction
switch is placed in either the left or right position, current flow is from the turn
signal/multifunction switch assembly to the turn signal/hazard flasher module. The
turn signal/hazard flasher module then sends an on-off voltage signal to either the
left or right turn signals and their instrument panel cluster (IPC) indicator. When
the hazard switch is pressed, all the turn signal lamps will flash including both
IPC turn signal indicators. The left turn signals have ground at G106, G400 and at
G402. The right turn signals have ground at G105 and G400. The turn signal/multifunction
switch supplies battery positive voltage to the cornering lamps, the left cornering
lamp has ground at G106 and the right cornering lamp has ground at G105.
Stop Lamps
The STOP fuse in the fuse block - left underhood 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, the right stop lamp and the CHMSL have ground at G400 and
G402.
Lighting System Indicators
The lighting indicators consist of the following:
| The lamp control module (LCM) illuminates the high beam indicator in the instrument
panel cluster (IPC) when the LCM detects that the high beams are requested. The IPC
sends a class 2 message to the body control module (BCM) indicating the status
of the indicator. |
| The head up display (HUD) illuminates the high beam indicator when the IPC sends
a signal requesting illumination. |
| The left and right turn signal indicators are hard wired to the turn signal
switch and the hazard switch. The turn signal indicator illuminates when the turn
signal lamps supply voltage circuit is active. If the IPC determines that the turn
signal is active for more than 1.29 kilometer (0.8 mile), the IPC sends
a class 2 message to the BCM in order to activate an audible warning. |
• | Turn Signals (with HUD) |
| The HUD illuminates the turn signal indicators when the IPC sends a signal requesting
illumination. |
Battery Run Down Protection/Inadvertent Power
To provide battery run down protection the body control module (BCM) used in
this vehicle controls the lighting system through circuits that enable both the exterior
lamp functions of park lamp and headlamp as well as the interior lamps. The BCM opens
these enabling circuits 10 minutes after the ignition switch is turned OFF
with no lamp switch activity. If the ignition switch is turned to any position other
than OFF, or if a lamp switch is activated, during this 10-minute period the timer
will reset for another 10 minutes.
If the headlight 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.
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.