Description And Operation; Exterior Lighting Systems Description And Operation - GMC Chevy Colorado 2023 Manual

2-26 Lighting

Description and Operation

Exterior Lighting Systems
Description and Operation
The exterior lighting system consist of the following
lamps:
Backup lamps
Cargo lamps
Daytime running lamps (DRL)
Exterior courtesy lamps
Hazard warning lamps
Headlamps
Park, tail, license, and marker lamps
Front fog lamps (T3U)
Stop lamps
Task lamps
Turn signal lamps
Trailer lighting, refer to
Operation on page 2 42
Headlamp Controls
The A11 Radio is used to determine headlamp mode
between AUTO, ON, Park, and OFF. When the user
selects the desired headlamp mode, the Radio sends
out a serial data message to multiple modules
containing headlamp mode status information. The
modules that receive the serial data message respond
accordingly. The headlamps may be turned ON in 3
different ways utilizing the A11 Radio controls:
When the headlamp mode is placed in the ON
position, for normal operation
When the headlamp mode is placed in the AUTO
position, for automatic lamp control during low
ambient light conditions
When the headlamp mode is placed in the AUTO
position, with the windshield wipers ON in daylight
conditions, after a 6 second delay
Low Beam Headlamps
The K219 Lighting Control Module responds to low
beam requests by applying pulse width modulated
(PWM) voltage to both headlamp low beam control
circuits, illuminating the low beam headlamps. When
the Lighting Control Module commands the low beam
headlamps ON, the operator will notice the interior
backlighting for the instrument cluster and the various
other switches dim to the level of brightness selected
by the instrument panel dimmer switch.
High Beam Headlamps
The high beam and flash to pass (FTP) functions are
contained within the S78 Turn Signal Switch. The
K9 Body Control Module (BCM) provides the turn
signal/multifunction switch with two signal circuits, the
high beam signal circuit and the FTP signal circuit.
When the low beam headlamps are ON, and the turn
signal/multifunction switch is placed in either the high
beam position or FTP position, ground is applied to the
BCM through the high beam/FTP signal circuit. The
BCM responds to the high beam request by sending a
serial data message to the K219 Lighting Control
Module. The Lighting Control Module responds by
Trailering Description and
for more information.
applying pulse width modulated (PWM) voltage to both
headlamp high beam control circuits, illuminating the
high beam headlamps. The status of the high beam
lamps is shown by a blue indicator located on the
instrument cluster. When high beams are commanded
on, the indicator will be illuminated continuously. If the
driver turns the high beams off, the indicator will also
turn off.
Flash to Pass
When the S78 Turn Signal Switch is momentarily
placed in the flash to pass position, ground is applied to
the turn signal/multifunction switch. The turn signal/
multifunction switch applies ground to the K9 Body
Control Module (BCM) through the flash to pass switch
signal circuit. The BCM responds to the flash to pass
request by sending a serial data message to the
K219 Lighting Control Module. The Lighting Control
Module responds by applying pulse width modulated
(PWM) voltage to both headlamp high beam control
circuits, illuminating the high beam headlamps. This
causes the high beam headlamps to illuminate at full
brightness until the turn signal/multifunction switch is
returned to the at rest position.
Automatic Headlamp Control
When the headlamp mode is in the AUTO position, the
BCM relies on the B10D Sun Load and Ambient Light
and Security Indicator Sensor input to determine if
headlamps are required or if daytime running lamps will
be activated based on outside lighting conditions.
During automatic lamp control, the headlamps will be
off during daylight conditions but will turn on when the
ambient light sensor detects low ambient light
conditions. The ambient light sensor is a light sensitive
transistor that varies the voltage signal to the BCM. The
BCM provides a 5 volt reference signal and a low
reference ground to the ambient light sensor. During
low light conditions the BCM will request the low beam
headlamps ON by sending a serial data message to the
K219 Lighting Control Module. The Lighting Control
Module responds by applying pulse width modulated
(PWM) voltage to both headlamp low beam control
circuits, illuminating the low beam headlamps.
Intellibeam Automatic High Beam
Assist (TQ5)
The IntelliBeam system is activated by selecting the
automatic high beam assist with the A11 Radio controls
while the exterior lamp control is in AUTO mode and
the engine running. The AHBA system consists of a
front camera module that detects light, and is able to
identify approaching vehicles on an even, straight road
at a distance of greater than 0.4 km (0.25 mi). The front
camera module analyzes light color, intensity, and
movement. The AHBA system will turn OFF the high
beam headlamps when approaching vehicle
headlamps or preceding vehicle taillights are detected
by the front camera module. The AHBA system is
turned off anytime the headlamp mode is out of the
AUTO position.
AHBA System Activation
Vehicle ON
Headlamp mode placed in the AUTO position
2023 - Colorado Electrical Body Builder Manual