Santa Fe L4-2.4L (2001)
Air Bag Control Module: Description and Operation
The SRS airbag system has sophisticated electrical and electronic components. Therefore the airbag operating components should be handled very
carefully.
SRSCM (Supplement Restraint System Control Module)
SRSCM determines when to deploy the airbag module by sensing the frontal and side impact force through the built in sensor SRSCM.
1. DC/DC convertor: The DC/DC convertors of the power supply includes a step up and a step down converter, which provide the firing voltage for
six 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 electromechanical switch which closes if it experiences a deceleration exceeding a specified threshold.
3. Back-up power: The SRSCM has emergency energy reserves to provide deployment energy for a short period when the vehicle voltage is low or if
lost in a vehicle frontal crash.
4. Malfunction detection: The SRSCM continuously monitors the current SRS operation status while the ignition key is turned on and detects a
malfunction of the system. The malfunction can be displayed in the form of diagnostic trouble code using Hi-scan.
5. MIL (Malfunction Indication Lamp) notification: If any fault is detected, the SRSCM sends a signal to the indicator lamp on the cluster to warn the
vehicle's driver.
The MIL indicator is the key to driver notification of SRS faults. Verify lamp and SRSCM operation by observing the flashing 6 times when the
ignition switch is first turned on.
6. Malfunction recording: Once a fault occurs in the system SRSCM records the fault in the memory in the form of DTC and the DTC is erased by
Hi-scan.
7. Data link connector: The SRSCM memory stored data are linked through this connector located at the underneath of driver side crash pad to an
external output device such as Hi-scan.
8. After firing the airbags once, the SRSCM cannot be used again and must be replaced.
9. Crash output
The crash output is used to control an external device which will unlock the doors in case of a crash event. The crash output is specified as follows
0 - 200 micro-amps in OFF mode and 200 mA in ON mode. In case of an unlock command the switch is closed for 200 ms.
