Geely EC715 2009, Workshop Manual

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9.2.3 System Working Principle
9.2.3.1 System Working Principle
Airbag Warning Lamp
Airbag warning lamp is located inside the instrument cluster
assembly, used to notify the driver airbag system failures and
examine whether the airbag control module is communicating
with the instrument panel. Turn the ignition key to "ON"
position, the airbag control module carry out system self-test.
If the system is normal, warning lamps flash 7 s and off. If a
malfunction is detected, airbag control module will store a
diagnostic trouble code (DTC), and then through the CAN-Bus
serial data bus, instruct the instrument cluster to light the airbag
warning lamp. After the vehicle starts, airbag control module
will continue to test each loop. If there is a malfunction, airbag
control module will communicate with the instrument cluster
through the CAN-Bus serial data bus, the airbag warning lamp
will be lit in 5 s. If there is a fault, airbag may fail to deploy, or
deploy when the crash does not reach the set collision severity.
If the airbag warning lamp is lit, please repair the vehicle at the
authorized service station as soon as possible. Before the
repair is completed, the airbag warning lamp will not be off.
Airbag Control Module
Note
Airbag control module has a back up power supply,
which can deploy the airbag, even if the battery voltage
is lost during a collision. Disconnect the battery negative
cable for at least 90s to empty the stored power supply,
before carry out the airbag system repair.
Airbag control module is a microprocessor, which is the airbag
system control center. When a collision happens, the airbag
control module will compare the signal from the sensor with the
value stored in the memory. When the generated signal
exceeds the stored value, the airbag control module will
command (electric current signal) to deploy airbags. When the
airbags are deployed, the airbag control module will record the
status of airbag systems, and light the airbag indicator on the
instrument cluster. After the vehicle starts, airbag control
module will continue to monitor the airbag system electrical
components and circuits. If an airbag control module
malfunction is detected, it will store a diagnostic trouble code,
and light the airbag warning lamp to inform the driver that a
malfunction exists.
Front Collision Sensor (Left / Right)
Front collision sensors are used to enhance the airbag system
performance. Front collision sensor is an acceleration sensor,
which sends the acceleration signal to the airbag control
module. Front collision sensor can help determine the severity
of a frontal collision. Airbag control module uses the measured
acceleration values to calculate and compare these calculated
values with values stored in the memory. When the calculated
value exceeds the value stored, the airbag control module will
issue a positive ignition command (electric current signal) to
activate the front airbag and seat belt pretensioner.
Driver Side Collision Sensor, Passenger Side
Collision Sensor
Each side collision sensor includes a sensing device for
monitoring vehicle acceleration to send vehicle lateral
acceleration signal to the airbag control module. Side collision
sensors can determine the severity of the side collision. Airbag
control module uses the measured acceleration values to
calculate and compare these calculated values with values
stored in the memory. When the calculated value exceeds the
value stored, the airbag control module will send a positive
ignition command (electric current signal) to activate the curtain
airbags, side airbags and seatbelt pretensioners.
Passenger Recognition Sensor
Passenger recognition sensor is located inside the passenger
seat cushion assembly and used to sense whether the
passenger seat is occupied by a passenger. It is a variable
resistance-type pressure sensor and senses the pressure
through the resistance changes. When the passenger seat is
occupied by a passenger, the seat belt warning lamp will be lit
to inform the driver to remind the passenger to fasten the seat
belt.
Driver Front Airbag, Passenger Front Airbag
Driver front airbag, passenger front airbag module includes a
shell, inflatable airbag, a detonating device and gas generating
agent. When the front collision impact force is large enough,
the airbag control module will command the front airbags to
deploy. Electric current flows through the ignition and activates
the gas generating agent to rapidly produce large amounts of
gas. The gas inflates the airbag. The airbag, once filled with the
gas, will deflate through holes in the airbag. Airbag control
module harness connector (driver front airbag, passenger front
airbag deployment circuits) has a short film. When the
connector is disconnected, the airbag deployment short circuit
will prevent the airbag accidental deployment during the repair.
Safety Protection Device Airbag System 9-5
EC718/EC718RV EC715/EC715RV 10/2009