SSANGYONG KORANDO 2013 Service Manual

Seat belt pretensioner deployment
Original status 1.
Pretensioner operating 2.
Load limiter operating 3.
Inflator PistonThe piston and pinion in the seat belt
pretensioner are disengaged and the tension of
the return spring in it holds the occupant.
When the ignition current is transmitted from the
air bag unit to the ignition device of the seat belt
pretensioner, gas is generated from the inflator
and this pushes up the piston.
When the piston gear engages with the pinion
gear, the clutch is integrated and winds the seat
belt.
When the load on the seat belt increases and the
inner device stars being deformed, the pinion
rotates in reverse direction and the piston moves
downward. The residual pressure is released
through the vent hole of the piston when the
piston moves down. The gears of pinion and
piston are disengaged when the piston is located
at the lowest position. Pinion

8810-00
4) Air Bag Deployment Signal to BCM
The air bag deployment signal from the air bag unit is sent to the BCM. This signal triggers the flash of
the hazard warning lamp to notify others of emergency situation, and is used as a signal that turns on the
room lamps and activates auto door unlock function for the occupants.
The air bag unit of a vehicle without side air bag system can also send the crash signal to the BCM
according to the value of the acceleration sensor to activate the auto door unlock and various lamps
including hazard warning lamp and room lamps.

When a situation which requires an air bag deployment occurs, they system outputs the air bag
deployment signal (crash out). If another air bag-required situation occurs while the deployment signal is
sent, the second crash out will be delayed until the current 200 ms crash out is completed. (The
The signal repeats increasing for 390 msec. and decreasing for 10 msec. before crash. At the time of
crash, the air bag deployment signal is output to the BCM for 200 ms immediately.
(1) Air bag deployment signal output (crash out)

8810-00
Operation 2.
Signal from unlock relay is output for 5 seconds (T3) after 40 ms (T2)
When turning IGN OFF during 5 seconds (T3) of unlock relay signal output
Signal from unlock relay is input for the rest of the time B.
C.
D.
E. Operation 1.
Air bag deployment signal is not input for initial 7 seconds (T4) after IGN ON A.
The room lamp comes on when the air bag deployment signal is input except when the room lamp
switch is turned off.
The hazard warning lamp flashes when the air bag deployment signal is input.
Resetting the auto door unlock function turns off the battery (cutting off BCM power). -
-
-
(2) BCM control when air bag deployment signal is input
The UNLOCK by the air bag deployment signal takes priority over the LOCK/UNLOCK control from
other functions.
The LOCK/UNLOCK requests from other functions during or after the UNLOCK output by the air
bag signal are ignored. However, the LOCK control is carried out when the ignition switch is turned
to the "OFF" position.
The same request during the LOCK/UNLOCK output is ignored. However, the UNLOCK by the air
bag deployment signal or operation by the smart key is carried out.
When LOCK and UNLOCK outputs occur at the same time, the LOCK output is carried out and
UNLOCK is ignored. 1.
2.
3.
4.

4. AIR BAG SYSTEM SELF DIAGNOSIS
1) Air Bag Unit (SDM) Self Diagnosis
The air bag unit monitors the internal/external devices of the air bag system including battery voltage,
limits certain functions of the air bag, and turns on the air bag warning lamp on the instrument cluster
according to the conditions.
Conditions for detecting and clearing faults
The time for detecting errors and clearing the errors is as follows:
Monitoring system Diagnosis
cycleTime for
detectingTime for
clearingClearing fault
Inflator circuit 400 ms 4 seconds 8 seconds with a diagnostic device
warning lamp circuit 100 ms 4 seconds 8 seconds with a diagnostic device
Battery voltage 10 ms 4 seconds 4 seconds with a diagnostic device
Impact sensor IGN ON 1 seconds2 to 4
seconds
(next Ign)with a diagnostic device
Impact record
(air bag deployed)-
Immediately-
by replacing SDM
(cannot be cleared with a
diagnostic device)
SDM internal fault--
by replacing SDM
(cannot be cleared with a
diagnostic device)

8810-00
Air bag warning lamp
2) Air Bag Warning Lamp
The air bag unit turns on the air bag warning lamp on the instrument cluster for 6 seconds after IGN ON
while performing self diagnosis for the air bag system. If no fault is found in the system, it turns off the
warning lamp. After this, the unit monitors the system regularly, and notifies the driver by turning on the
air bag warning lamp when a fault is found in the system.
System normal
Comes on for 6 seconds after IGN ON and then goes out.
The air bag warning lamp comes on when: *
diagnosis is performed for the inside/external devices of
the system when the ignition is turned on
the air bag system is malfunctioning
the air bag unit and a diagnostic equipment communicate
each other -
-
-
(1) Air bag warning lamp ON at initial IGN ON

System malfunctioning
Comes on for 6 seconds after IGN ON and goes out for 1 second, and then remains on.
(2) Air bag warning lamp operation during driving
The air bag warning lamp comes on when the air bag unit (SDM) detects a system malfunction. The
warning lamp goes out when the malfunction disappears.

8810-00
3) Supply Voltage Monitoring
The air bag unit monitors the battery voltage continuously while the ignition is turned on.. It limits certain
functions of the air bag system and outputs DTC and air bag warning lamp signal according to the result
of the monitoring.
Abnormal voltage of the air bag unit (too high/too low) is determined to be fault only when the signal
is detected for continuous 4 seconds.
Emergency power function
The SDM has an emergency power 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. Full emergency
power capability is available after the minimum specified operating voltage has been applied to the
SDM power line for 10 seconds, and from this point, air bag deployment and EDR are enabled.

4) Internal monitoring
The air bag unit checks the status of the air bag system and monitors the system for internal errors. If
an error is detected by self diagnosis, this unit disables part of the air bag system functions and outputs
a diagnostic trouble code (DTC) and air bag warning lamp signal.
Watchdog
The micro controller is monitored periodically. And if a fault is found, micro controller is reset, inflator
ignition function is limited, and the air bag warning lamp comes on. -
Air bag operations for errors
Internal errorsAir bag operation
Front air bag system Side air bag system
X-axis acceleration sensor
error
DisabledDisabled
Y-axis acceleration sensor
errorDisabled
Z-axis acceleration sensor
erroravailable
ROM checksum error Disabled
RAM checksum error Disabled
NVM checksum error Disabled
Internal acceleration sensor test
The air bag unit checks internal acceleration sensor when the ignition is turned on. The air bag unit
determines the deployment of the air bag for the collision signal input after the diagnosis. -
Non-volatile memory (NVM) test
The air bag unit checks the values stored in the memory. If the values are not correct, the air bag unit
sets a diagnostic trouble code (DTC) and turns on the air bag warning lamp. -

8810-00
5) External monitoring
The air bag unit supplies a certain level of test current and monitors the resistance of the inflator circuit
within a specified range to deploy the air bag. It limits certain functions of the air bag, sets a DTC and
turns on the air bag warning lamp according to the conditions.
Inflator circuit resistance monitoring