Restraints

General Information

General

The Supplemental Restraint System (SRS) is designed to supplement the seat belts to reduce the risk or severity of injury to the driver and passenger by activating and deploying the driver, passenger, side airbags and seat belt pretensioners in certain frontal or side collisions. The SRS (Airbag) consists of: the driver airbag module, located in the center of the steering wheel, which contains a folded airbag and inflator unit; the passenger airbag module, located in the passenger side dashboard, which contains a folded airbag assembly with inflator unit; the side airbag modules, located in the front seatbacks, which contain folded airbag and inflator; and the curtain airbag modules, located inside the headliner, which contain folded airbags and inflator units. The impact detection function of the SRSCM is performed by an electronic accelerometer, which continuously measures vehicle acceleration and sends a corresponding signal through amplification and filter circuits to the microprocessor. The SRSCM (SRS Control Module) detects frontal and side collisions using the side impact sensor and determines airbag module deployment.

1. 1
   DC/DC Converter: The DC/DC converter in the power supply unit includes a step-up/step-down transformer converter and provides the ignition voltage for the 2 front airbag ignition circuits and the internal operating voltage of the SRSCM. If the internal operating voltage falls below the critical value, the SRSCM is reset.
2. 2
   Backup Power Supply: The SRSCM has a separate backup power supply that instantly supplies deployment energy in the event of low voltage or power failure during a frontal collision.
3. 3
   Self-Diagnosis: The SRSCM continuously monitors the current operating status of the SRS and detects system malfunctions while the vehicle power is on. System malfunctions can be checked using diagnostic trouble codes (DTCs) with the GDS.
4. 4
   Airbag Warning Lamp: When a malfunction is detected, the module sends a signal to the SRS warning lamp located on the instrument panel. The MIL will indicate an SRS driver malfunction. When the ignition is turned on, the SRS lamp will illuminate for approximately six seconds.
5. 5
   Fault Code Recording: When a malfunction occurs in the SRS, the SRSCM stores the corresponding DTC. DTCs can only be erased using the GDS. However, if an internal malfunction code is recorded or a failure is recorded, the fault must not be cleared.
6. 6
   Self-Diagnosis Connector: Data stored in the SRSCM memory is output to the GDS or other external output devices through the connector located under the driver side airbag.
7. 7
   After the airbag has deployed, the SRSCM must not be reused and must be replaced.
8. 8
   Side airbag deployment will be determined by the SRSCM, which detects the impact signal from the satellite sensor during a side collision, regardless of seat belt status.

Specifications

Specification

Item	Resistance (Ω)
Driver Airbag (DAB)	1,7 - 2,3
Passenger Airbag (PAB)	1,7 - 2,3
Side Airbag (SAB)	1,9 - 2,5
Curtain Airbag (CAB)	1,7 - 2,5
Seat Belt Pretensioner (BPT)	1,8 - 2,5

Tightening Torque

Item	N·m	kgf·m	lbf·ft
Driver Airbag (DAB)	7,8 - 10,8	0,8 - 1,1	5,8–8,0
Passenger Airbag (PAB)	7,8 - 11,8	0,8 - 1,2	5,8 - 8,7
Curtain Airbag (CAB)	7,8 - 11,8	0,8 - 1,2	5,8 - 8,7
Knee Airbag (KAB)	7,8 - 11,8	0,8 - 1,2	5,8 - 8,7
Seat Belt Anchor Bolt	39,2 - 53,9	4,0 - 5,5	28,9 - 39,8
Emergency Fastening Device (EFD)	39,2 - 53,9	4,0 - 5,5	28,9 - 39,8
SRSCM	7,8 - 9,8	0,8 - 1,0	5,8 - 7,2
Side Impact Sensor (SIS) Mounting Bolt	7,8 - 9,8	0,8 - 1,0	5,8 - 7,2
Frontal Impact Sensor (FIS) Mounting Bolt	8,0 - 10,0	0,8 - 1,0	6,0 - 7,4

Special Service Tools

Special Service Tools

Tool Name/Number	Illustration	Description
Deployment Tool 0957A-34100A		Used to deploy the airbag
Deployment Adapter 0K57A-3U100A		Use with deployment tool (0957A-34100A) when deploying DAB, PAB, CAB, BPT, EFD.
Deployment Adapter 0957A-3F100		Used with the deployment tool (0957A-34100A) when deploying KAB
Deployment Adapter 0957A-2W100		Used with the deployment tool (0957A-34100A) when deploying SAB
Dummy Unit 0957A-38200		Airbag Wiring Harness Resistance Check Simulator
Dummy Adapter 0957A-2W200		Used with the dummy (0957A-38200) when checking SAB resistance
Dummy Adapter 0957A-3F000		Used with the dummy (0957A-38200) when checking KAB resistance
Dummy Adapter 0957A-2G000		Used with the dummy (0957A-38200) when checking DAB, PAB, CAB, BPT, EFD resistance

DAB: Driver Airbag; PAB: Passenger Airbag; SAB: Side Airbag; CAB: Curtain Airbag; KAB: Knee Airbag; BPT: Seat Belt Pretensioner; EFD: Emergency Fixing Device

General Safety Information and Precautions

Precautions

General Precautions

Before performing service on the airbag system, carefully read the following precautions. Follow the instructions described in this manual, otherwise the airbags may deploy accidentally and cause damage or injury.

• Except when inspecting electrical equipment, always turn the ignition key OFF, disconnect the negative battery cable, and wait at least three minutes before starting work.

• Use replacement parts manufactured to the same standards and quality as original parts. Do not install used SRS parts from another vehicle. When repairing the SRS, use only new parts.
• Carefully inspect any SRS component before installation. Do not install any part that shows signs of being dropped or mishandled, such as dents, cracks, or deformation.

  

• Before removing any SRS parts (including disconnecting connectors), always disconnect the SRSCM connector.

Airbag Handling and Storage: Do not disassemble the airbag; it has no serviceable parts. Once an airbag has deployed, it cannot be repaired or reused. Observe the following precautions when temporarily storing an airbag during service.

• Store the removed airbag with the pad facing up.
• Do not allow oil, grease, cleaning agents or water to contact the airbag unit to prevent damage to the airbag assembly.

  

• Store the removed airbag on a secure, flat surface away from any heat sources (temperature above 85 °C/185 °F).
• Never perform electrical tests on airbags, such as measuring resistance.
• Do not stand in front of the airbag unit during removal, inspection or replacement.
• Refer to the disposal procedures for a deployed or damaged airbag.
• Be careful not to strike the SRS unit or side impact sensors. Whenever the ignition key is in the ON position, wait at least three minutes after the ignition key is turned OFF before starting work.
• During installation or replacement, be careful not to strike the area around the SRS unit and side impact sensor (with an impact wrench, hammer, etc.). Airbags may deploy accidentally and cause damage or injury.
• Replace the front airbag module and SRSCM if the front airbag has deployed. Replace airbag wiring if the airbag wiring is damaged. Replace the side airbag module, curtain airbag module, SRSCM, and SIS if the side airbag has deployed. Replace the airbag wiring if the airbag wiring is damaged.
• After a collision in which the airbags or side airbags did not deploy, inspect the SRS unit and side impact sensors for damage or deformation. If damaged, replace the SRS unit and side impact sensors.
• Do not disassemble the SRS unit or side impact sensors.
• Turn the ignition OFF, disconnect the negative battery cable, and wait at least three minutes before starting installation or replacement of the SRS unit.
• Make sure the SRS unit and side impact sensors are securely fastened with the mounting bolts.
• Do not spill water or oil on the SRS unit or side impact sensors, and protect them from dust.
• Store the SRS unit and side impact sensors in a cool (15–25 °C / 59–77 °F) and dry (relative humidity 30–80%, no moisture) place.

Connection Precautions: SRS wiring can be identified by its special yellow outer covering. Observe the instructions described in this section.

• Never attempt to modify, splice or repair SRS wiring. If the SRS wiring is open or damaged, replace the harness.

  

• Make sure the harness wires are routed so that they are not pinched and do not interfere with other components.

  

• Make sure all SRS ground points are clean and the grounds are securely fastened for optimal metal-to-metal contact. Poor grounding may cause intermittent problems that are difficult to diagnose.

Electrical Inspection Precautions

• When using electrical test equipment, insert the tester probe into the connector from the wire side. Do not insert the tester probe into the terminal side of the connector and do not tamper with the connector.

  

• Use a U-shaped probe. Do not force the probe into the connector.
• Use the specified service connectors for troubleshooting. Using improper tools may cause an incorrect check result due to poor metal contact.

Spring-Loaded Lock Connector: Some SRS connectors have a spring-loaded lock. Airbag connector

Disconnection

To unlock the connector, pull the spring-loaded sleeve (A) and slider (B) while holding the opposite half of the connector. Disconnect the connector halves. Always pull on the sleeve, not on the connector half.

Connection

While holding both connector halves, push until the projection (C) on the sleeve side of the connector locks with a click.

Description and Operation

Warning Lamp Activation

Warning Lamp Behavior After Ignition ON

As soon as the operating voltage is applied to the SRSCM ignition input, the SRSCM activates the LED warning lamp for a lamp check. The lamp should illuminate for 6 seconds during the initialization phase and then turn off. To warn the driver, the warning lamp illuminates for 6 seconds and turns off for one second, then remains on continuously after the operating voltage is applied if any active malfunction exists.

1. 1
   Active malfunctions are present.

   

2. 2
   No active malfunctions or fault records.

   

3. 3
   When the ignition is turned on in variant coding (EOL) mode, the airbag warning lamp illuminates and flashes at 1-second intervals until coding is completed. If variant coding is completed normally, the airbag warning lamp illuminates for 6 seconds and then turns off. Otherwise, the airbag warning lamp continuously flashes at 1-second intervals.

   1. If variant coding is completed normally

      

   2. If variant coding is not completed

      

   When an active malfunction exists in the airbag system or an internal malfunction of the SRSCM is present, variant coding (EOL) cannot be completed. In this case, repeat the variant coding (EOL) procedure after troubleshooting with the GDS.
4. 4
   Loss of SRSCM battery power: warning lamp remains on continuously.
5. 5
   Loss of internal operating voltage: warning lamp remains on continuously.
6. 6
   Loss of microprocessor operation: warning lamp remains on continuously.
7. 7
   SRSCM not connected: warning lamp remains on continuously.

Independent Activation of SRS Warning Lamp: There are certain failure conditions under which the SRSCM cannot function and therefore cannot control the airbag warning lamp. In these cases, the airbag warning lamp is activated directly by the corresponding circuit, which operates independently of the SRSCM. These cases are:

Repair Procedures

Replacement of Components After Deployment

If the front airbags deployed after a collision, replace the following items.

• SRSCM
• Deployed airbag(s)
• Seat belt pretensioner(s)
• Front impact sensors
• Inspect the clock spring for heat damage. If damage is found, replace the clock spring.

If the side/curtain airbags have deployed after a collision, replace the following components.

• SRSCM
• Deployed airbag(s)
• Side impact sensor(s) on the deployed side(s)

After completing all repairs to the vehicle, make sure the SRS airbag system is functioning properly.

• Turn the ignition ON; the SRS indicator should illuminate for approximately six seconds, then turn off.

Components and Component Location

Components

1. Driver Airbag (DAB) 2. Clock Spring 3. Steering Wheel 4. Seat Belt Pretensioner (BPT) 5. Passenger Airbag (PAB) 6. Side Airbag (SAB)

7. Curtain airbag (CAB) 8. Frontal impact sensor (FIS) 9. Knee airbag (KAB) 10. Pressure-type side impact sensor (P-SIS) 11. Supplemental restraint system control module (SRSCM) 12. Emergency fastening device (EFD) 13. Front gravity impact sensor