The supplemental inflatable restraint (SIR) is a safety device used in conjunction with the seat belt. The air bag does not replace the function of the seat belt. The driver and the passengers must always fasten their seat belts and adjust them for a proper fit.
The SIR is designed to protect the driver and the front seat passenger in the event of a significant frontal impact to the vehicle. The air bags deploy if the force is applied from a direction within 30 degrees of the vehicle's center line.
The SIR system consists of the following components:
• | Driver air bag module |
• | Driver side air bag module |
• | Passenger air bag module |
• | Passenger side air bag module |
• | Driver and front passenger seat belt pretensioners, and load limiter for some models |
• | Sensing and diagnostic module (SDM) |
• | Clock spring |
• | Wire harness and connectors |
• | AIRBAG indicator on the instrument cluster |
• | Passenger AIRBAG OFF indicator on the clock screen (North America Vehicles) |
• | Side air bag sensor |
• | Occupants classification system (sensor and module) (North America Vehicles) |
• | Early crash sensor (North America Vehicles) |
Caution: Refer to SIR Caution in the Preface section.
The driver air bag module is under the center pad of the steering wheel. The driver air bag module contained an igniter charge and a gas generator to inflate the folded air bag.
The air bag connector contains a shorting bar which makes the circuit shorted when the connector is disconnected. The shorting bar prevents current from travelling through the driver air bag module during servicing. The shorting bar is disengaged when the connector is connected.
Caution: Refer to SIR Caution in the Preface section.
The passenger air bag module is on the passenger part of the instrument panel (I/P). The passenger air bag module contains an igniter charge and a gas generator to inflate the folded air bag.
The air bag connector contains a shorting bar, which makes the circuit shorted when the connector is disconnected. The shorting bar prevents current from travelling through the passenger air bag module during servicing. The shorting bar is disengaged when the connector is connected.
Caution: Refer to SIR Caution in the Preface section.
The passenger air bag module is on the passenger part of the instrument panel (I/P). The passenger air bag module contains an igniter charge and a gas generator to inflate the folded air bag.
The air bag connector contains a shorting bar, which makes the circuit shorted when the connector is disconnected. The shorting bar prevents current from travelling through the passenger air bag module during servicing. The shorting bar is disengaged when the connector is connected.
The passenger airbag module will not deploy if OC(Occupants Classification) sensor can not detect any weight on the passenger seat or if there is no weight on the passenger seat or if there is under 46kg on the passenger seat. In case of this, you can see Passenger Air Bag OFF indicator on the clock screen.
On the other hand, if there is a passenger over 46kg on the passenger seat, you can not see Passenger Air Bag OFF indicator on the clock screen. And this means the passenger airbag is ready to be deployed for frontal impact.
Caution: Refer to SIR Caution in the Preface section.
The side airbag modules are in the driver’s and passenger’s seats. The side airbag module contains an igniter charge and a gas generator to inflate the folded airbag .
The air bag connector contains a shorting bar, which makes the circuit shorted when the connector is disconnected. The shorting bar prevents current from travelling through the side air bag module during servicing. The shorting bar is disengaged when the connector is connected.
Caution: Refer to SIR Caution in the Preface section.
The seat belt pretensioners, with load limiter for some vehicles, are assembled with each front seat belt retractor to retract the seat belt webbing when accounted frontal collision. The seat belt pretensioners are controlled by the sensing and diagnostic module (SDM). The seat belt pretensioner contains an igniter charge and a gas generator to pull the seat belt webbing. The seat belt pretensioner must be replaced after an accident that causes its activation.
The seat belt pretensioner also contains a shorting bar to prevent current from travelling through the seat belt pretensioner during servicing. The shorting bar is disengaged when the connector is connected.
Caution: Be careful when you handle a sensing and diagnostic module (SDM). Do not strike
or jolt the SDM. Before applying power to the SDM:
• Remove any dirt, grease, etc. From the mounting surface. • Position the SDM horizontally on the mounting surface. • Tighten all of the SDM fasteners and SDM bracket fasteners to the specified
torque value.
The sensing and diagnostic module (SDM) is located on the floor beneath the floor console assembly. The SDM performs the following functions:
• | Monitors the supplemental inflatable restraints (SIR) electrical components and sets a DTC when malfunction is detected |
• | Records any faults that are discovered |
• | Displays SIR DTCs and system status information when connected to a scan tool |
• | Illuminates the Air Bag indicator to alert the driver to any fault |
• | Provides a reserve power source to deploy the air bags and pretensioners if an accident has disabled the normal power source |
• | Monitors vehicle velocity changes to detect frontal impacts, which are severe enough to warrant deployment |
• | Causes current to flow through the air bag modules and pretensioner to cause deployment if a frontal impact of sufficient force is detected |
The SDM contains no user-serviceable parts.
The instrument cluster contains an Air Bag Warning indicator and sensing and diagnostic module (SDM). The SDM performs a turn-on test when the ignition is turned ON.
The SDM flashes the Air Bag indicator 7 times by supplying an intermittent ground to the indicator lamp circuit. After flashing 7 times, the Air Bag indicator will turn OFF if no more malfunctions have been detected.
If the SDM has detected malfunctions in the internal and external circuits, which could potentially affect the operation of the supplemental inflatable restraints (SIR), the Air Bag indicator stays ON. Some malfunctions could result in non-deployment when necessary or deployment under conditions which would not normally result in deployment.
When the SDM is not properly attached to its connector, the air bag circuit is shorted to ground because there is a shorting bar in the SDM electrical connector. The shorting bar is disengaged when proper connection is made, but if a poor connection exists the SDM connector supplied a ground to the Air Bag indicator independently of the SDM, and the Air Bag indicator turns ON.
Caution: Improper routing of the wire harness assembly may damage the inflatable restraint steering wheel module coil. This may result in a malfunction of the coil, which may cause personal injury.
Notice: Do not rotate the steering wheel or move the position of the steering gear once the intermediate shaft is disconnected. This will uncenter the Inflatable Restraint coil in the steering column. If the Inflatable Restraint coil becomes uncentered, it may be damaged during vehicle operation.
There is a coil assembly in the steering which is referred to as a clock spring because of its internal resemblance to the type of spring used in a mechanical clock. The coil spring should never be disassembled, and there is no time keeping function. The clock spring contains 2 or 3 current-carrying coils. One of the current-carrying coils maintains continuous contact within the driver deployment loop while the steering wheel is rotated. The clock spring also contains coils that maintain continuous contact for horn and remote audio control switch circuit.
Turning the steering wheel in one direction tightens the coil, and turning the steering wheel in the opposite direction loosens the coil. Do not turn the clock spring when the steering wheel is not attached. For proper installation of the clock spring, refer to Inflatable Restraint Steering Wheel Module Coil Replacement .
The clock spring also includes the wiring and the connectors for the horn circuit and the driver air bag circuit. A yellow 2-way connector on the lower steering column is attached to the clock spring wiring. The yellow connector to the air bag contains a shorting bar which connects the driver high circuit to driver low circuit when the connector is disconnected.
The shorting bar prevents current from travelling through the driver air bag module during servicing. The shorting bar is disengaged when the clock spring connector is connected.
OCS determines passenger airbag deployment. In consists of a sensor and module which are in the passenger seat. The passenger airbag will deploy for frontal impact only when OCS sensor detects a over 46kg passenger on the passenger seat. OCS is not unit repairable so it should be replaced with an assembly of passenger seat.
ECSs are located on both LH and RH side of longifudinal. ECS detects frontal impact of the vehicle and transmits the information to the SDM. OCS is not unit repairable so it should be replaced with an assembly of passenger seat.