SSANGYONG korando C200 Service Manual - page 37
02-39
AIR BAG SYSTEM
korando 2010.10
8625-03
Firing loop phase - Front air bag
▶
Each firing loop consists of a high side and low side switch. The current is limited by the ASIC
to 2 to 4 A. Both stages of the front air bags are fired by the energy reserve capacitors.
Firing loop - Side air bag
▶
The firing loop consists of a high side and low side switch. The current is limited by the ASIC to
2 to 4 A. The side air bag is fired by the battery power supply.
Firing loop - Belt pretensioner
▶
The firing loop consists of a high side and low side switch. The current is limited by the ASIC to
2 to 4 A. The belt pretensioner is fired by the battery power supply.
Energy reserve and autonomous operating time
▶
The SDM has an energy reserve function that ensures the internal operation of the central unit
and buffering firing circuits for a minimum of 150 ms after loss of battery power. The SDM
cannot detect a crash or deploy the air bag for up to 5 sec after cutting off the battery voltage
from the SDM . Full energy reserve capability is available for 10 sec after the minimum
specified operating voltage has been applied to the SDM power line. The SDM checks for
charging and discharging conditions by measuring the energy reserve capacitor. If there is any
problem in the energy reserve capacitor, it sets a diagnostic trouble code associated with an
energy reserve function.
Orthogonal acceleration sensor
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The integrated electrical acceleration sensor provides an electrical signal of the vehicle's
acceleration along the orthogonal axis and longitudinal axis. The electrical signals are
proportional to the acceleration. Those signals are evaluated by the micro controller via the A/D
converter. The firing threshold is adjustable by parameter setting for the corresponding
algorithm. If the adjusted value exceeds the threshold value, the SDM will drive the high side
and low side transistors of the corresponding firing loops.
Arming/Safety circuit
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The trigger switch which controls power is implemented as an arming/safety sensor in the SDM.
It is only used in the front air bag firing loops and it puts the front air bag firing circuits to the
armed status under the air bag deployment conditions and maintains the air bag firing circuits
unarmed under the normal driving conditions. All components in the safety circuit can be tested,
so a high level of reliability can be achieved. The trigger sensor is continuously monitored to
prevent the belt pretensioner loop from activating with the operating conditions not satisfied. It
is allowed to be activated only when a loop closing is detected.