Kia Optima: SRSCM / SRS Control Module (SRSCM)

Description and operation

The primary purpose of the SRSCM (Supplemental Restraints System Control Module) is to discriminate between an event that warrants restraint system deployment and an event that does not. The SRSCM must decide whether to deploy the restraint system or not. After determining that pretensioners and/or airbag deployment is required, the SRSCM must supply sufficient power to the pretensioners and airbag igniters to initiate deployment.

The SRSCM determines that an impact may require deployment of the pretensioners and airbags from data obtained from impact sensors and other components in conjunction with a safing function.

The SRSCM will not be ready to detect a crash or to activate the restraint system devices until the signals in the SRSCM circuitry is stabilized.

It is possible that the SRSCM could activate the safety restraint devices in approximately 2 seconds but is guaranteed to fully function after prove-out is completed.

The SRSCM must perform a diagnostic routine and light a system readiness indicator when the ignition switch is in the ON position. The system must perform a continuous diagnostic routine and provide fault notice through a warning lamp indicator in the event of fault detection. A serial diagnostic communication interface will be used to facilitate servicing of the restraint control system.

Components and components location

Schematic diagrams

Repair procedures

1.	Disconnect the battery negative terminal. After disconnecting the cables, wait at least 3 minutes.

After replacing the SRSCM with a new one, the "Variant Coding" procedure MUST be performed.

1) In SRSCM variant coding mode, the airbag warning lamp periodically flickers (ON: 0.5sec., OFF: 0.5sec.) until the coding is normally completed. 2) If the variant coding has failed, DTC (ACU Coding Error) will be displayed and the warning lamp will be turned on. In this case, perform the variant coding procedure again after confirming the cause in “DTC Fault State Information”. Variant Coding can be performed up to 255 times, but if the number of coding work exceeds 255 times, DTC (Exceed Maximum coding Number) will be displayed and SRSCM must be replaced. 3) If the battery voltage is low (less than 9V), DTC will be displayed. In this case, charge the battery before anything else, and then perform the variant coding procedure. DTC (ACU Coding Error) and (Battery Voltage Low) may be displayed simultaneously.

Variant coding Procedure