Suzuki GRAND VITARA Owner's Manual page 1466

9B-4 Lighting Systems:
Front and rear height sensors
Height sensor (1) is installed to the front and rear suspension frames respectively and connected to the lower arm (4)
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]
1
Headlight leveling control module
Headlight leveling control module is installed at the foot of the front passenger seat. 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
2
3
4
[A]: Front
[B]
2
1
[B]: Rear
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.
3
4
I5JB0A920005-01
Warning light
OFF
OFF
OFF
ON
ON
ON
OFF