The SRS airbag system has sophisticated electrical and electronic components. Therefore the airbag operating
components should be handled very carefully.
The SRSCM will deploy the airbag modules by sensing the frontal impact sensed by the sensor built in to the SRSCM.
etc. Otherwise it could cause the airbag system to unexpectedly deploy during servicing.
SRSCM
1. DC/DC convertor : The DC/DC converter in the power supply includes a step-up and a step-down converter, which
provides the firing voltage for four firing circuits and the internal operating voltage. If the internal operating voltage falls
below a defined threshold, a reset is executed.
2. Arming sensor/safing sensor : The arming/safing sensor built in to the airbag firing circuit has the function of arming the
airbag circuit under all required deployment conditions and maintaining the airbag firing circuits unarmed under normal
driving conditions. The safing sensor is a dual-contact electro mechanical switch that closes if it experiences a
deceleration exceeding a specified threshold.
3. Back-up power : The SRSCM reserves an energy reserve to provide deployment energy for a short period when the
vehicle voltage is low or if lost in a vehicle frontal crash.
4. Back-up power : The SRSCM reserves an energy reserve to provide deployment energy for a short period when the
vehicle voltage is low or if lost in a vehicle frontal crash.
5. Malfunction detection : The SRSCM continuously monitors SRS operating status while the ignition key is turned on and
detects possible malfunctions in the system. The malfunction can be displayed in the form of a diagnostic trouble code
using the Hi-Scan Pro.
6. MIL (Malfunction Indication Lamp) notification : If any fault is detected, the SRSCM sends a signal to the indicator lamp
on the instrument cluster to warn the vehicle driver.
The MIL indicator is the key item in notifying the driver of SRS faults. It verifies lamp and SRSCM operation by flashing
6 times when the ignition switch is first turned on.
7. Malfunction recording : Once a fault occurs in the system, the SRSCM records the fault in memory in the form of a
DTC, which can only be erased by the Hi-Scan Pro.
8. Data link connector : SRSCM memory stored is linked through this connector located under neath the driver side crash
pad to an external output device such as the Hi-Scan Pro.
9. What if only BPT's deploy.
10. Crash output
The crash output is used to unlock the doors in case of a crash. The crash output is : 0 ~ 200
µ
A in OFF mode and
200mA in ON mode. During the unlock command, the switch is closed for 200 mS.
DIAGNOSIS WITH SCAN TOOL
CHECK PROCEDURES
1. Connect the Hi-Scan Pro DLC to the vehicle's data link connector located underneath the dash panel.
2. Turn the ignition key to the "ON" position and turn the Hi-Scan Pro ON.
3. Perform the SRS diagnosis according to the vehicle model configuration.
4. If a fault code is assured, then replace the component. Never attempt to repair the component.
5. If the Hi-Scan Pro finds that a component of the system is faulty, there is a possibility that the fault is not in the
component, but in SRS wiringor connector.
SPECIFICATION
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24.04.2008
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