2010 Cadillac CTS Sedan AWD V6-3.6L Page 389
Circuit/System Description
Battery positive voltage is applied to the headlamp control module at all times. The headlamp control module has a normal operational voltage
range of about 12.5-16 V and is only fully functional with the ignition switch is in the RUN position and the headlamp switch in the AUTO
position. The communications enable signal from the BCM 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 adaptive forward lighting system
(AFL) 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 (DIC) located on the instrument panel cluster (IPC).
Conditions for Running the DTC
* Battery voltage must be between 9-16 V.
* Ignition is in the RUN or ON position.
* Headlamp switch is in the AUTO position.
* High or low beam headlamps must be active.
* Vehicle speed greater than 2 mph.
* Transmission is in the DRIVE position.
Conditions for Setting the DTC
DTC B1461 00
The headlamp control module detects a short to voltage or an open/high resistance on any of the left headlamp actuator control circuits.
DTC B1461 02
The headlamp control module detects a short to ground on any of the left headlamp actuator control circuits.
DTC B1461 39
The headlamp control module detects an internal electronic failure.
DTC B1461 54
The headlamp control module detects an overheating condition on any of the left headlamp actuator control circuits.
DTC B1462 00
The headlamp control module detects a short to voltage or an open/high resistance on any of the right headlamp actuator control circuits.
DTC B1462 02
The headlamp control module detects a short to ground on any of the right headlamp actuator control circuits.
DTC B1462 39
The headlamp control module detects an internal electronic failure.
DTC B1462 54
The headlamp control module detects an overheating condition on any of the right headlamp actuator control circuits.
