Interior Lighting Systems Description And Operation; Interior Lighting System; Interior Lamps - GMC Chevy Colorado 2023 Manual

2-28 Lighting
Turn Signal Outage Detection
Vehicles with LED turn signals require additional turn
signal outage detection circuits that provide turn signal
feedback to the K219 Lighting Control Module. The
Lighting Control Module uses the feedback information
to send a serial data message to the instrument cluster
to alert the driver anytime a turn signal fault is detected.
If a fault is detected on a turn signal circuit or a turn
signal feedback circuit, the turn signals will flash in a
rapid manner to alert the driver of the fault.
Backup Lamps
With the engine running and the transmission in the
reverse position, the transmission control module
(TCM) sends a serial data message to the multiple
control modules. The message indicates that the gear
selector is in the reverse position. The K9 Body Control
Module (BCM) responds to the reverse position
message by sending a serial data message to the
K219 Lighting Control Module to request the backup
lamps on. The Lighting Control Module responds by
applying battery voltage to the backup lamps control
circuit(s) illuminating the backup lamps. The applied
voltage is also sent to the A11 Radio and A10 Inside
Rearview Mirror for rearview camera purposes. Once
the driver moves the gear selector out of the reverse
position, a serial data message is sent by the TCM that
the transmission is no longer in the reverse position.
The BCM responds to the reverse position message by
sending a serial data message to the Lighting Control
Module to request the backup lamps off. The Lighting
Control Module responds by removing battery voltage
from the backup lamp circuits. The engine must be
running for the backup lamps to operate.
Cargo Lamps
When the K219 Lighting Control Module receives a
cargo lamp request from the A11 Radio controls, the
lighting control module responds by applying pulse
width modulated (PWM) voltage to the cargo lamp
control circuits illuminating the cargo lamps. In the
event that the cargo lamps were to remain illuminated
for more than 10 minutes with the ignition switch in the
OFF position, the lighting control module will deactivate
the cargo lamp control circuits to prevent total battery
discharge.
Approach Lighting
Approach lighting is commanded ON when the unlock
button is pressed on the keyless entry transmitter
during dark ambient light conditions. When the keyless
entry transmitter unlock button is pressed, a serial data
message is sent by the K9 Body Control Module (BCM)
that the vehicle is being unlocked. The K219 Lighting
Control Module responds to the serial data message by
applying voltage to the approach lamp control circuit
illuminating the LED lighting located under each outside
rearview mirror as part of approach lighting.
Battery Run Down Protection/
Inadvertent Power
To provide battery run down protection, the exterior
lamps will be deactivated automatically under certain
conditions. The K9 Body Control Module (BCM)
monitors the state of the S30 Headlamp Switch. If the
headlamp switch is in the park or headlamp position
when the ignition switch is ON and then the ignition
switch is placed in the OFF position, the BCM initiates a
10 minutes timer. At the end of the 10 minutes, the BCM
will send a serial data message to the K219 Lighting
Control Module to deactivate the exterior lamps to
prevent total battery discharge. This feature will be
cancelled if any power mode other than OFF becomes
active.
The BCM will disable battery run down protection if any
of the following conditions exist:
The park or headlamp switch is changed from the
ON to OFF position, and back to the ON position
during battery run down protection.
The BCM determined that the park or headlamp
switch was not active when the ignition was
turned OFF.
Interior Lighting Systems
Description and Operation

Interior Lamps

Dome Lamps
The dome lamps are controlled by door ajar inputs to
the K9 Body Control Module (BCM). When any door is
opened, the door ajar switch contacts close and the
BCM receives a door-open input. The BCM responds
by sending a serial data message to the A103 Roof
Console. The Roof Console responds by applying
battery voltage to the dome lamps illuminating the
dome lamps. The BCM will also send a serial data
message to request the dome lamps on when a door
lock/unlock request is activated with the key fob. After
all doors have been closed, the dome lamp will remain
illuminated approximately 3 seconds after the last door
closes. In the event that the dome lamp were to remain
illuminated for more than 10 minutes with the ignition
switch in the OFF position, the BCM will deactivate the
dome lamp control circuit to prevent total battery
discharge. The dome lamps will turn OFF using the
theater dimming feature when controlled by the BCM.
Keyless Entry Interior Illumination
When the operator uses the keyless entry transmitter in
order to unlock the doors, the K9 Body Control Module
(BCM) receives a door-unlock signal. The BCM must
receive inputs from various systems that indicate that
the ignition switch is OFF, the courtesy lamp switch is
OFF, and all doors are closed before the BCM will
activate the interior lamps. After all doors have been
closed, the courtesy lamps will turn OFF immediately if
the ignition switch is turned to the ON position, the door
locks are LOCKED, or approximately 20 seconds after
the last door closes. The BCM will turn off the courtesy
lamps through the theater dimming feature. The BCM
keeps the courtesy lamps on for 40 seconds after an
alarm event is completed.
Reading Lamps
When a reading lamp button is pressed, the switch
contacts close providing a path to ground for the signal
circuit from the A103 Roof Console. The roof console
responds by applying battery voltage to the appropriate
reading lamp control circuit illuminating the reading
lamp. If the operator inadvertently leaves a reading
2023 - Colorado Electrical Body Builder Manual