Published by Hyundai Motor company, september 2005 SRS AIR BAG Centennial

2 The supplemental restraint system (SRS AIRBAG) is designed to supplement the seat belt to help reduce the risk or severity of injury to the driver and passenger by activating and deploying the driver, passenger, side airbag and belt pre-tensioner in certain frontal or side collisions. The SRS (Airbag) consists of : a driver side airbag module located in the center of the steering wheel, which contains the folded cushion and an inflator unit ; a passenger side airbag module located in the passenger side crash pad contains the folded cushion assembled with inflator unit ; Side airbag modules located in the driver and passenger seat contain the folded cushion and an inflator unit. SRSCM located on the floor under the heater core which monitors the system, an accelerometer which senses the vehicle deceleration, a spring interconnection (clock spring) located within the steering column ; system wiring and wiring connector; and a knee bolster located under the steering column. The impact sensing function of the SRSCM is carried out by electronic accelerometer that continuously measure the vehicle's acceleration and delivers a corresponding signal through amplifying and filtering circuitry to the microprocessor. GENERAL

3 1. Be sure to proceed airbag related service after approx. 30 seconds or longer from the time the ignition switch is turned to the LOCK position and the negative (-) terminal cable is disconnected from the battery. The airbag system is equipped with a back up power source to assure the deployment of airbag when the battery cable is disconnected by an accident. The back up power is available for approx. 150ms. 2. When the negative (-) terminal cable is disconnected from the battery, memory of the clock and audio systems will be canceled. So before starting work, make a record of the contents memorized by the audio memory system. When the work is finished, reset the audio system and adjust the clock. 3. Malfunction symptoms of the airbag system are difficult to confirm, so the diagnostic codes become the most important source of information when troubleshooting. CUSTOMER CAUTIONS Failure to carry out service operations in the correct sequence could cause the airbag system to unexpectedly deploy during servicing, possibly leading to a serious injury. Further, if a mistake is made in servicing the airbag system, it is possible that the airbag may fail to operate when required. Before performing servicing (including removal or installation of parts, inspection or replacement), be sure to read the following items carefully.

4 4. When troubleshooting the airbag system, always inspect the diagnostic codes before disconnecting the battery. 5. Never use airbag parts from another vehicle. When replacing parts, replace them with new parts. 6. Never attempt to disassemble and repair the airbag modules (DAB, PAB, SAB, BPT), clock spring and wiring in order to reuse them. 7. If any component of SRS has been dropped, or if there are cracks, dents or other defects in the case, bracket or connector, replace them with new ones. 8. After work on the airbag system is completed, perform the SRS SRI check. The airbag indicator lamp can be interrupted by other circuit fault in some cases. Therefore if the airbag indicator lamp goes on, be sure to erase the DTC codes using Hi-scan just after repairing or replacing the troubled parts including fuse. 9. Especially in case of welding the body, never fail to disconnect the battery negative (-) terminal. CUSTOMER CAUTIONS

5 APPLICATION SDM - GH – : DAB + PAB + 2BPT – : DAB + PAB + FSAB + 2BPT – : DAB + PAB + RSAB + 2BPT (LZ) – : DAB + PAB + RSAB + 2BPT (YJ) – : DAB + PAB + FSAB + RSAB + 2BPT DAB: Driver Airbag PAB: Passenger Airbag FSAB: Front Side Airbag RSAB: Rear Side Airbag BPT: Belt Pretensioner

6 FUNCTIONS OF AIRBAG Absorbs kinematics energy of occupants. Protects occupants from interior trims. Protects occupants from broken glass. Reduces occupants neck load by kinematically restraining spin of neck.

7 ASSEMBLY (DAB & Steering) DAB Steering Wheel Clock Spring Multi Function Switch Steering angle sensor

8 DEPOWERED AIR BAG March 1997, NHTSA in U.S.A. announced that vehicle manufacturers can depower (reduce the inflation pressure) all airbags so that they inflate less aggressively. * Depowering of 20 to 35 percent of the severity (inflator) * Purpose of ensuring the female and child * Added the neck injury criteria - Flexion Bending Moment 190 Nm - Extension Bending Moment 57 Nm - Axial Tension 3300 peak N - Axial Compression 4000 peak N - Fore-and-after Shear 3100 peak N * Widely plan to apply to 98MY * Be allowed until Aug. 31, 2001.

9 GENERAL MAJOR COMPONENT –SRS CM –LABLES FOR INFORMATION –STEERING COLUMN & WHEEL –D.A.B. MODULE –P.A.B. MODULE –S.A.B. MODULE –PASSENGER PRESENCE DETECTION –SEAT BELT PRETENTIONER (Driver & passenger) –SRS SRI –BUCKLE SWITCH –WIRING HARNESS

10 - The airbag must be inflated 80% when the driver reaches 125mm forward displacement - The airbag (driver=60 l, passenger=120 l) takes 30ms to reach 80% inflation - 125mm forward displacement is reached after 40-80ms depending on the impact velocity - The Fire / No Fire decision must be reached by the crash algorithm 10-50ms after impact - The optimum firing time is obtained by: * Crash film analysis Double integral of acceleration TFire = T125mm Forward Displacement - 30ms Airbag Inflation Time OPTIMUM FIRING TIME CACULATION

11 CONTROL MODULE (ESPS) T.B.D. angle Within 30 °from vehicle's centerline : LAW Within 45 °from vehicle's centerline : Maker Hard object The vehicle crashed a deer with 80 Km/h, but the airbag did not operate. T.B.D. velocity Frontal Crash : - 10 MPH : Must NO FIRE - 15 MPH : UN-BELT -A/BAG Fire, BELT- Pretensioner Fire - 19 MPH : Must fire Pretensioner & A/BAG together Side Crash: - FMVSS KPH : A/BAG FIRE - EC REGULATION 30KPH : A/BAG FIRE

12 BAGS LOCATION PAB DABFASB-FRT-L FSAB-FRT-RFSAB-RR-R FSAB-RR-L

13 LOCATION FIS RSAB FSAB SIS BPT DABCAB PAB ACU

14 CLOCK SPRING Clock Spring

15 AIRBAG MODULE (DAB) Inflator Assembly (Full power) Mounting plate (Reaction Plate) Module cover (Trim cover) Hidden "H"-pattern tear seam Bag : coated L 2-VENT HOLES

16 DAB MODULE Module cover Inflator assembly Warning label Reacting plate

17 INFLATOR ASSEMBLY (DRIVER'S SIDE) SRS AIRBAG - COMPONENTS PYROTECHNIC INFLATOR Ignition system 2. Autoignition charge 3. Inflator housing 4. Filter system 5. Initiator 6. Gas generator 7. Connector with integral shorting clip

18 DAB CONNECTOR DAB Connector

19 PAB

20 AIRBAG MODULE (PAB) Inflator Assembly (Full Power) Mounting plate Module cover (Trim cover) U-pattern tear seam Bag : not coated L No-VENT HOLES

21 PAB Mounting bracket Inflator assembly Warning label Connector

22 AIRBAG MODULE (FSAB) Inflator Assembly Mounting plate Module cover (Trim cover) Bag : not coated L No-VENT HOLES

23 AIRBAG MODULE (FSAB) - LOCATION RSAB R/H Module RSAB L/H Module FSAB L/H Module FSAB R/H Module PAB Module DAB Module

24 SIDE AIRBAGS Front Side Airbag Rear Side Airbag

25 FSAB Satellite sensor The release system for the side airbag consists of a SRE-SMART installed in the middle of the vehicle and two satellite - one on the left-hand side and one on the right-hand side.

26 FSAB The SRE-SMART is capable of releasing the airbags or the seat-belt pretensioners systems in the vehicle. In the dialog between the SRSCM and the satellite, it is the SRSCM which takes the release decision. The SRSCM is supported in connection with the side airbag function by the two satellites, which act as intelligent acceleration sensors and such as back up the central airbag controller. Both the satellites continuously report the current system status on the left and right- hand sides of the vehicle to the SRSCM. It monitors the acceleration sensor continuously. The test results are reported to the SRSCM by means of periodic status signals.

27 FSAB Specifications Voltage The full functionality of the system PDL pin to GND pin: 7V - 17V Power consumption The maximum power of 0.72W occurs 10 seconds after the 12V is connected. Temperature Ambient temperature: -40 °C to +85 °C Self test The satellite runs a self-test to check internal components as soon as the operating voltage is applied to the PDL pin. These components are as follows: - ROM - RAM - Acceleration sensor - EEPROM If a fault is detected in the ROM, RAM or Acceleration sensor, a fault signal is transmitted permanently to the SRSCM. If a fault is detected during the self-test cycle, the satellite use the default parameter setting in the ROM, and continues to transmit the fault signal and remains capable of detecting a side impact.

28 FSAB - OPERATION CrashImpact Sensing Sending Signal to SRSCMSRSCM operates FSAB

29 FSAB - OPERATION FSAB is deployed: 26 liter

30 FSAB - OPERATION DAB PAB If there is no front passenger, then the Passenger Side Airbag will not be deployed.

31 FILTER - FUNCTIONS –Filtering hazardous gas –Cooling generated gas –Decrease the noise - FOLDS OF FILTER Primary filter Secondary filter Fine mesh screen Deflector

32 WIRING HARNESS53 All airbag circuits are designated as such and contained in a special overlay harness. Color coding and unique identification in proper locations throughout the overlay harness is recommended. Front end wire routings and connections should be reviewed with particular emphasis on the airbag circuits, maintaining electrical continuity in the event of collision.

33 LOCATION OF CONTROL MODULE & SENSORS Satellite sensor - R/H Satellite sensor - L/H RSAB - R/H RSAB - L/H PPD sensor FSAB - R/H FSAB - L/H Buckle switch ACU PAB DAB FIS

34 CONTROL MODULE (SDM-GH) The primary functions are 1. DC/DC converter: DC/DC converter in power supply unit includes up/down transformer converter, and provide ignition voltage for 2 front airbag ignition circuits and inside operation voltage. If inside operation voltage is below critical value setting, it will perform re- setting. 2. Safety sensor: Safety sensor is located in airbag ignition circuit. Safety sensor will operate airbag circuit at any deployment condition and release airbag circuit safely at normal driving condition. Safety sensor is a double contact electro-mechanical switch that will close detecting deceleration above certain criteria. 3. Back up power supply: SRSCM has separate back up power supply, that will supply deployment energy instantly in low voltage condition or upon power failure by front crash. 4. Self diagnosis: SRSCM will constantly monitor current SRS operation status and detect system failure during vehicle power supply is on, system failure may be checked with trouble codes using scan too. (Hi-Scan)

35 5. Airbag warning lamp on: Upon detecting error, the module will transmit signal to SRSCM indicator lamp located at cluster. MIL lamp will indicate driver SRS error. Upon ignition key on, SRS lamp will blink 7 times to indicate operation. 6. Trouble code registration: Upon error occurrence in system, SRSCM will store DTC corresponding to the error. DTC can be cleared only by Hi-Scan. 7. Self diagnostic connector: Data stored in SRSCM memory will be output to Hi-Scan or other external output devices through connector located below driver seat crash pad. 8. Once airbag is deployed, SRSCM should not be used again but replaced. 9. SRSCM will determine whether passenger has put on seat belt using built-in switch signal in seat belt buckle, and deploy front seat airbag at each set crash speed. 10. Side airbag deployment will be determined by SRSCM that will detect satellite sensor impact signal upon side crash, irrespective to seat belt condition. CONTROL MODULE (SDM-GH)

36 CONTROL MODULE (SDM-GH) Main Functions The SRS airbag system consists of sophisticated electrical and electronic components. Be cautious in handling the airbag operation parts. Longitudinal and orthogonal central acceleration sensor One firing circuit with Energy Reserve for 1 st stage DAB Two firing circuit without Energy Reserve for Frontal BPT Warning lamp for system fault display One Service Communication Interface (K-Line), same as SRE-HMC Driver and Passenger BS Monitoring and Status-Recording

37 CONTROL MODULE (SDM-GH) Optional Functions - One firing circuit with Energy Reserve for 1 st stage PAB - Two firing circuit with Energy Reserve for 2 nd DAB & PAB - Up to two firing circuits without Energy Reserve for Front Side Airbags - Two Side Impact Satellites Interfaces - Two Early Crash Sensor Interfaces - PPD system Monitoring and Status-Recording

38 CONTROL MODULE (SDM-GH) Measurements in the start up phase Watchdog EEPROM, ROM, RAM Warning Lamps Autonomous Operating Time High Side Switch and Low Side Switch Test Acceleration Sensor

39 CONTROL MODULE (SDM-GH) Cyclic Measurement After the start up phase the microcontroller is executing cyclic test on following modules / parts: A/D Converter Battery Voltage Firing Loops Warning Lamps Firing voltage internal Electrical Sensor (PPD) Safing Sensor (Trigger Switch) Satellite Interface Early Crash Sensor Buckle Switches

40 Backup firing path Firing V (25V) 5V Test Safing sensor Firing circuit 1 DAB Microcontroller (ROM, RAM, EEPROM, A/D, SCI) One-Chip accelerometer Self-Test Accelerometer Amplifier filter Test SRI driver Watchdog Test Power supply SRI Battery SRSCM BLOCK DIAGRAM (SDM-GH) Firing circuit 2 PAB Firing circuit 3 DSBP Firing circuit 4 PSBP Diagnostic interface Firing circuit 5 DBPT Firing circuit 6 PBPT Buckle Switch Warning Lamp ECS Option Satellite Interface

41 FUNCTIONS (SDM - GH) Internal electromechanical safing sensor. Crash detection, calculation of firing time. Internal electronic acceleration sensing element. Self-test, cyclic monitoring of critical components. SRI activation circuitry with optional monitoring. Storage of faults in non-volatile memory. Energy reserve to provide autonomous operation. Optional crash recording. Provision of 6 airbag firing circuit. 1-wire bi-directional communication interface.

42 SERVICE REMINDER INDICATOR (S.R.I.) Status Display –As soon as operating voltage is applied to the CM activates the SRI for a bulb check. The lamp shall blink 6 times for 6 seconds at 1HZ during the initialization phase and be turned off afterwards. –During the initialization phase, the CM will not be ready to detect a crash and deployment will be inhibited until the signals in the CM circuitry stabilize.

43 SERVICE REMINDER INDICATOR There are certain fault conditions in which the SRSCM (SRS Control Module) cannot function and thus cannot control the operation of the lamp. In these cases, the lamp is directly activated by appropriate circuitry that operates independently of the SRSCM, as follow. 1) Loss of ignition voltage supply to the SRSCM : Lamp turned on continuously. 2) Loss of internal operating voltage : Lamp turned on continuously. 3) SRSCM malfunctioning : Lamp turned on continuously. 4) SRSCM not connected : Lamp turned on through shorting bar in wiring harness connector.

44 Operating situationOperating method RUNNINGRUNNING Return to normal from temporary fault Faults frequency 5 Active fault ON OFF Turn it on continuously Blink 6 times Normal Faults frequency 4 On to off after 6 seconds Turn it on continuously STARTINGSTARTING Faults frequency 5 Active fault SERVICE REMINDER INDICATOR

45 - SIS (Side Impact Satellite)Part NO. SIDE IMPACT SENSOR OptionsPart No. DAB + PAB + FSAB + 2BPT B100 DAB + PAB + RSAB + 2BPT (LZ) B150 DAB + PAB + RSAB + 2BPT (YJ) B200 DAB + PAB + FSAB + RSAB + 2BPT B100

46 SEAT BELT PRETENSIONER Passive seat belt system Main construction - Gas generator - Cylinder & Piston - Winding wire - Tension reducer - Rack & Pinion gear - Force limiter - ELR mechanism ELR: Emergency Locking Retractor

47 PRETENTIONER - PYROTHECNIC TYPE Webbing Sensing mass ball Mounting bracket Retractor assembly Gas generator Cylinder

48 SEAT BELT PRETENSIONER CONNECTOR Seat Belt Pretensioner

49 SEAT BELT PRETENSIONER Function When a vehicle has crashed with a certain degree of frontal impact, the gas generator is made to ignite by the electrical firing signal from SRSCM. Gas from the gas generator causes movement of the piston in the manifold case (cylinder), which operates a rack gear. Finally the webbing is retracted by the rotation of the spool. Therefore the seat belt pretensioner helps to reduce the severity of injury tot he front occupant by retracting the seat belt webbing to prevent the occupant from moving forward and hitting the steering wheel or instrument panel when the vehicle is crashed.

50 SEAT BELT PRETENSIONER Force Limiter The force limiter is designed to relieve the impact force to an occupants chest of the seat belt webbing when the occupant is restrained by the seat belt during a crash. If the crash force reaches a certain value, the torsion bar in the pretensioned seat belt is deformed and this causes the webbing to be extracted from the seat belt thus relieving the impact force. Rack Pinion Planet Gear

51 - Effective force transmission through use of rack & pinion gear type pretensioner. - Stable load and free stroke by torsion bar type force limiter. - Pretensioner with long travel retraction. - Mechanical and Electrical types are available. * Caution A pretensioner functions one time only. Be sure to replace the pretensioner seat belt as new one after activation of it. CHARACTERISTICS OF PRETENTIONER

52 PRETENTIONER – PYROTECHNIC TYPE Tension reducer Webbing Sensing mass ball Mounting bracket Retractor assembly Maker: Tokai Rika (Japan) Supplier: Samsong (Korea) Gas generator Cylinder

53 Tension reducer connecter Pretensioner connecter Locking clip Locking clip Pretensioner connecter Tension reducer PRETENTIONER – PYROTECHNIC TYPE

54 SEAT BELT PRETENSIONER CONNECTOR

55 PRETENTIONER Service procedure - Installation The pyrotechnical triggering ignition system is integrated into the retractor and forms one single component and the pretensioner is operated by an electrical signal. Care should be taken when handling the pretensioner seat belt. Before installation, disconnect the battery (-) terminal, with the ignition key on off position. When installing and removing the pretensioner, do not tap or bang it. - The pretensioner seat belt must be correctly mounted according to the specified location and direction. - Only connect the battery after installation of the pretensioner seat belt has been correctly completed.

56 PRETENTIONER Service procedure - Removal It is absolutely necessary to remove the pretensioner seat belt in the sequence described before page. - Make sure that ignition is on off position. - Disconnect the battery (-) terminal and, make sure it does not come into contact with the body. - Wait for about I minute. - Pull off the plug from the appropriate connector at the gas generator. - Loosen the belt and remove the belt from the vehicle body.

57 The Load Limiter is designed to restrain the passenger by the seat belt from moving forward in case of an accident. In order to protect the passenger from injury, the torsion bar installed in the seat belt will be deformed when pressure between chest and the belt reaches 500kg/cm 2 or more, so that it reduces the impact by releasing the seat belt. LOAD LIMITER Load < 5.5kN wind belt constantly Load = 5.5kN do not wind belt, torsion bar deformed Torsion bar Spindle

58 Resistance of 402 Ohms ±10% (Closed Switch) as UNBUCKLED Resistance of 1006 Ohms ±10% (Open Switch) as BUCKLED Buckle Status Change 2sec. Maximum test voltage 5.0 Volts Maximum measurement current< 20 mA Maximum current is limited< 100 mA Groundshift from ECU to Buckle Switch must be < 200 mVolts The buckle switches are cyclic polled. A state is changed if 5 cycles of corresponding resistance measure are accumulated. BUCKLE SWITCHES

59 Belted (Buckled) : 4 K ± 10% Unbelted (Unbuckled) : 1 K ± 10% Type: Micro switch type SEAT BELT BUCKLE SWITCH

60 Dual Threshold Algorithm depending on Buckle switch NO Seat belt buckle switch status DAB operating Threshold BPT operating Threshold FastenHigh thresholdLow threshold UnfastenLow thresholdNo trigger 1 2 Low threshold Fault or initial fault diagnosis Not optional switch 3 4 SEAT BELT BUCKLE SWITCH

61 PPD PPD Sensor is located on the Front Passenger Seat. It detects the front passenger seat is occupied or not.

62 The passenger presence detection system detects the presence of front passenger on the seat. The system is designed primarily to prevent replacement of airbag components that activate needlessly in an accident. The PPD system consists of a weight sensor. The threshold for PPD is as follows; - Occupied :15 kg or more - Not occupied : 0.6 kg or less The sensor characteristics is defined: - RP 50 KΩ for W 15 kg - RP > 50 KΩ for W < 0.6 kg (RP: Resistance of force sensing resistor) (W: Mass of weight) PPD

63 PPD (Passenger Presence Detection) General The passenger presence detection(PPD) system detects the presence of Passenger in the seat. The system is designed primarily to prevent replacement of airbag components that fire needlessly in accident. The PPD system consists of a weight sensor and interface unit. The weight sensor use the technology of the Force Sensor Resistor(FSR) of IEE. This technology proven and reliable the threshold for passenger presence detection is: - occupied : 15 kg - not occupied : 0.6 kg - Detecting 0.6~15kg: gray zone PPD interface unit will detect passenger presence using the PPD resistance change. Upon switching from passenger presence to passenger absence, it will admit passenger absence after 9.6 seconds for mis- determination. (for improved safety)

64 PPD (Passenger Presence Detection) PPD Interface and Connector

65 PPD (Passenger Presence Detection)

66 PPD (Passenger Presence Detection) Pin No.A (output to SRSCM)B (Resistance input from PPD) 1Battery powerSensor (-) 2Not usedSensor (+) 3Passenger presence or absenceNot used 4GroundNot used 5-

67 PPD (Passenger Presence Detection) Serial No. * 0 6 S * End mark Daily product No.: 001~999 Day: 1-31 Month: 1-9, X (October), Y (November), Z (December) Year: 98- Manufacturer code Type mark: 05 (front unit) 06 (rear unit) Beginning mark

68 CLOCK SPRING The clock spring (coil spring) consists of two current carrying coils. It is attached between the steering column and the steering wheel. It allows rotation of the steering wheel while maintaining continuous contact of the deployment loop through the inflator module. The steering wheel must be fitted correctly to the steering column with the clock spring at the neutral position, otherwise cable disconnection and other troubles may result.

69 CLOCK SPRING Neutral position indication The system includes ring gear (90 teeth) located at upper case, transparent cover installed at rotor with screw, and gear (80 teeth) interlocked with ring gear and driven by prominent part of the cover. Upper case is installed on the steering column at fixed position. Rotor is connected with steering column and always rotate with steering wheel. Gear is always interlocked with ring gear by prominent part of the cover. Rotor and prominent part of the cover will rotate together. Therefore, gear will rotate in reverse direction to rotor by 10 teeth difference with the ring gear. On the gear, R2, R1 NEUTRAL, L1 and L2 marks are embedded on every tenth teeth. Matching marks are on the upper case. Clock spring mark should match with gear's NEUTRAL mark when the vehicle is in straight forward position. Gear's R mark indicates rotor rotation clockwise and L counterclockwise. In order to center again, turn the steering wheel clockwise to the end, and thereafter turn counterclockwise about 3 revolution to match the mark.

70 DIAGNOSTIC TROUBLESHOOTING FLOW CHART

71 DIAGNOSTIC TROUBLESHOOTING Specification Caution Never measure the resistance any component for Airbag system 8mA for 2ms1.2A for 2ms1.75A for 2msAll-fire current 50mA / 10mACyclic test current 0.4A for 10sec650mA for 2 secNo-fire current 2.15 ± ± ± 0.2 Resistance BPTFSABDAB / PAB 90mA for 10sec 50mA 100mA

72 LOCATION OF DATA LINK CONNECTOR D.L.C.

73 DATA LINK CONNECTOR 16-PIN (Vehicle side connector: female)