Adaptive Forward Lighting

WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.

The AFL consist of the following components:

Headlamp control module
Headlamp actuator - left
Headlamp actuator - right

Courtesy of GENERAL MOTORS COMPANY

Callout	Component Name
DD	Serial Data - GMLAN High Speed
DD	Serial Data - GMLAN High Speed
DD	Serial Data - GMLAN High Speed
DD	Serial Data - GMLAN High Speed
DF	Serial Data Chassis Expansion Bus
DJ	Serial Data - Local Interconnect Network
DJ	Serial Data - Local Interconnect Network
K19	K19 Suspension Control Module
K9	K9 Body Control Module
K26	K26 Headlamp Control Module
K17	K17 Electronic Brake Control Module
B99	B99 Steering Wheel Angle Sensor
E13LA	E13LA Headlamp Assembly - Left
E13RA	E13RA Headlamp Assembly - Right

Battery positive voltage is applied to the headlamp control module at all times and when the ignition switch is in the RUN and CRANK positions. The headlamp control module has an operational voltage range of about 10.5-16 volts and is only fully functional when the ignition switch is in the RUN position. The voltage input from the ignition switch wakes the headlamp control module microprocessor. The headlamp control module receives serial data messages from the engine control module (ECM), transmission control module (TCM), electronic brake control module (EBCM), and body control module (BCM) with regards to power mode, speed, steering angle, transmission gear selection, and headlamp switch status. The headlamp control module calculates the headlamp angle and sends commands to the left and right headlamp actuators. The headlamp actuators drive the headlamps to the position commanded by the headlamp control module. The headlamp control module monitors the headlamp actuator motor control circuits for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a DTC will be stored in memory and the driver will be notified with a message displayed over the driver information center located on the instrument panel.

The headlamp control module controls the left headlamp movement by 15 degrees to the left and 5 degrees to the right, and the right headlamp movement by 5 degrees to the left and 15 degrees to the right. The direction the headlamps move is controlled by the steering wheel angle and is limited by steering angles of approximately +/- 90 degrees. The AFL will not operate with the transmission in reverse or at vehicle speeds less than 2 mph. Movement of the headlamps is restricted at low vehicle speeds and full movement of the lamps is not allowed until vehicle speed is greater than approximately 30 mph. The following conditions must be met before the adaptive forward lighting will operate:

Turn signal/multifunction switch in the AUTO position and high or low beam headlamps must be active
Steering angle position must be received from the EBCM with the steering signal validity bit set
Vehicle speed must be received from the ECM with the steering signal validity bit set
Transmission gear position must be received from the TCM with the transmission gear position validity bit set