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:

Steering Wheel Module

Caution: Refer to SIR Caution in the Preface section.

The steering wheel module is under the center pad of the steering wheel. The steering wheel 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 steering wheel module during servicing. The shorting bar is disengaged when the connector is connected.

I/P Module (Except North America Vehicles)

Caution: Refer to SIR Caution in the Preface section.

The I/P module is on the passenger part of the instrument panel (I/P). The I/P 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 I/P module during servicing. The shorting bar is disengaged when the connector is connected.

I/P Module (North America Vehicles)

Caution: Refer to SIR Caution in the Preface section.

The I/P module is on the passenger part of the instrument panel (I/P). The I/P 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 I/P 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.

Side Impact Module

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 impact 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:

The sensing and diagnostic module (SDM) is located on the floor beneath the floor console assembly. The SDM performs the following functions:

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 steering wheel module coil 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 steering wheel module coil 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 steering wheel module coil 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 steering wheel module coil when the steering wheel is not attached. For proper installation of the steering wheel module coil, refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

The steering wheel module coil 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 steering wheel module coil 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 steering wheel module during servicing. The shorting bar is disengaged when the steering wheel module coil 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.

If the SDM electrical connector is not attached properly, a built in shorting bar will connect the wire from the air bag warning lamp with the SDM ground wire. This turns ON the air bag indicator. To prevent deployment during servicing, additional shorting bars are located in the following locations:

The shorting bar is only a backup safety device. Always disable the SIR before beginning any service procedure.