Suzuki 2006 SX4 Service Manual page 1248

9B-4 Lighting Systems:
Front and rear height sensors
Front height sensor (1) is installed to the front suspension frame (2) respectively and connected to the lower arm (4)
with the link (3). Also rear height sensor is installed to the rear floor center cross member (5) respectively and
connected to the rear axle (6) with the link (3). Each height sensor converts vertical movement of the lower arm into
the resistance value and outputs the detected change in the vehicle position as a voltage signal to the headlight
leveling control module.
[A]
[A]: Front
Headlight leveling control module
Headlight leveling control module is installed at the inside of the glove box. It uses the headlight ON signal from the
lighting switch, vehicle speed signal from BCM and vehicle position signal from height sensors to calculate the angle
of the headlight optical axis to be corrected. Then it adjusts the optical axis angle of headlight based on the calculated
angle value by driving the headlight leveling actuator so that proper headlight aiming is obtained. Also, when any
abnormality is detected in the system, the headlight leveling control module makes the headlight leveling warning light
in the combination meter light up to warn the driver of an abnormality in the system.
Fail-safe function of headlight leveling control module
Headlight leveling control module has a fail-safe function which operates as follows.
Detecting condition
Power voltage supplied to headlight
leveling control module is higher than
18.5V
Power voltage supplied to headlight
leveling control module is lower than 9V
Vehicle speed is 180km/h or higher
Voltage supplied to height sensor is lower
than 4.6V
Signal voltage from height sensor is higher
than 4.75V or lower than 0.25V
Abnormality in headlight leveling control
module is detected
Correction value calculated by headlight
leveling control module exceeds operation
range of headlight leveling actuator
[B]
1
3
2
4
Fail-safe operation
Stops headlight leveling actuator operation.
Stops headlight leveling actuator operation.
Stops headlight leveling actuator operation.
Stops headlight leveling actuator operation.
Stops headlight leveling actuator operation.
Resets microcomputer in headlight leveling
control module.
Drives headlight leveling actuator within its
operation range.
1
3
[B]: Rear
5
6
I6RW0C920004-01
Warning light
OFF
OFF
OFF
ON
ON
ON
OFF