NISSAN THEORY OF OPERATION 1986-96 On 300ZX and 1989-90 Pulsar models, the airbags or SRS system will deploy if any of the crash location sensors or impact detectors (right-hand, center, left-hand or tunnel) and the safing sensor simultaneously activate while the ignition is On. On 1994-95 Quest and 1994 Altima, Maxima and Sentra models, the airbags or SRS system will deploy if any of the crash location sensors or impact detectors (front or tunnel) and the safing sensor simultaneously activate while the ignition is On.On 1995-96 Altima, Maxima, Sentra, 200SX, 240SX and 1996 Quest models, the airbags or SRS system will deploy if the diagnosis sensor unit activates while the ignition is in the On or Start position. On 1996 Truck 2WD and Pathfinder models, the airbags or SRS system will deploy if the diagnosis sensor unit activates while the ignition is in the On position. On 1996 Truck 4WD models, the airbag will deploy if the G sensor and/or crash zone sensor activates simultaneously with the safing sensor while the ignition is in the On position. When the ignition is turned to the On or Start, the airbag warning lamp should light for about seven seconds, then go off. This indicates the Supplemental Restraint System (SRS) (includes seat belt pretenssioners) is operating normally. A failure condition is present if the lamp is lit for seven seconds and flashes every half second, or if the lamp does not light. 1997-2011 ALTIMA, MAXIMA, PATHFINDER, SENTRA, 2005X & 240SX The Supplemental Restraint System (SRS) (includes seat belt pretenssioners) consists of airbag pyrotechnic or explosive device located on the steering wheel and on the passenger side of the instrument panel, sensors, diagnosis (control/sensor) unit, instrument panel warning lamp, wiring harness and spiral cable. Some of these models are also equipped with side airbags or SRS system which are built into the front seats and front seat belt pretensioners. On Maxima and 2002 Altima models, a crash zone sensor is located in the front center of the automobile, behind the grille.If the automobile is involved in a frontal accident or impact of sufficient force the driver's airbag module, passenger's airbag module and the seat belt pretensioners will deploy. The seat belt pretensioners with load limiters are equipped with an ELR shaft. During deployment, the seat belt pretensioner will take up seat belt slack to securely restrain front seat passengers. If the automobile passengers are thrown forward in a accident or impact and the restraining force of the seat belt exceeds the specified level, the load limiter will permit a specified extension of the seat belt in the chest area web by twisting the ELR shaft.The left-hand side airbag should only deploy if the left-hand side of the automobile is involved in a accident or impact of sufficient force. The right-hand side airbag should only deploy if the right-hand side of the automobile is involved in a accident or impact of sufficient force.The safing and G sensors for the driver's airbag module, passenger's airbag module and seat belt pretensioners are built into the diagnosis sensor unit. The safing sensor for the side airbags or SRS system is also built into the diagnosis sensor unit. Satellite sensors for the side airbags or SRS system are located on the B-pillars.The diagnostic (control/sensor) unit diagnoses the SRS circuit. When the ignition is in the On or Start position, the airbag warning lamp will light for approximately seven seconds, then go off. This indicates the system is operating properly.On 2002 Altima models there are left-hand and right-hand roof panel airbag pyrotechnic or explosive device which provide occupant upper body protection in the event of a corresponding side accident or impact. FRONTIER & XTERRA The Supplemental Restraint System (SRS) (includes seat belt pretenssioners) consists of a driver's airbag module located on the steering wheel, passenger's airbag module located on the right-hand side of the instrument panel, sensors, diagnosis (control/sensor) unit, instrument panel warning lamp, wiring harness and a spiral cable. The front seat belt retractors contain pretensioners that deploy to take up all belt slack in the event of a accident or impact. Xterra models are equipped with a crash zone sensor located in the front center of the automobile, behind the grille. Frontier models are also equipped with a key operated passenger's airbag deactivation switch. When this switch is turned to the On position, the passenger's airbag is enabled and is ready to deploy in a frontal accident or impact. When it is turned Off, the airbag is disabled and will not deploy if a accident or impact occurs. After the ignition has been turned On, the instrument panel deactivation lamp lights as a bulb inspection function and will stay lit if the deactivation switch is turned to the Off position. If the deactivation switch is turned On, the lamp should go out after approximately seven seconds. If the automobile is involved if a frontal accident or impact of sufficient force the driver's and passenger's airbag pyrotechnic or explosive device and the seat belt pretensioners will deploy. On Frontier models, the passenger's airbag will not deploy if the deactivation switch is turned Off.On all models, the diagnostic (control/sensor) unit diagnoses the SRS circuit. When the ignition is in the On or Start position, the airbag warning lamp will light for approximately seven seconds, then go off. This indicates the system is operating properly. QUEST The Supplemental Restraint System (SRS) (includes seat belt pretenssioners) consists of driver's airbag module located on the steering wheel, passenger's side airbag module located on right-hand side of instrument panel, diagnosis (control/sensor) unit, instrument panel warning lamp, wiring harness and spiral cable. The safing and G sensors for the driver's and passenger's airbag are built into the diagnosis sensor unit. When the automobile is involved in a frontal accident or impact of sufficient force the driver's and passenger's airbag pyrotechnic or explosive device will deploy. The safing and G sensors for the driver's and passenger's airbag are built into the diagnosis sensor unit. The diagnostic (control/sensor) unit diagnoses the SRS circuit. When the ignition is in the On or Start position, the airbag warning lamp will light for approximately seven seconds, then go off. This indicates the system is operating properly. Other Systems up to 2011 THEORY OF OPERATION The Supplemental airbag Restraint System deploys if the diagnosis sensor unit activates while the ignition switch is in the ON or START position.The control unit (diagnostic unit) diagnoses the SRS circuit. When the ignition key is in the ON or START position, the airbag warning lamp will illuminate for approximately 7 seconds, then turn off. This indicates the system is operating normally. The Supplemental Restraint System (SRS) (includes seat belt pretenssioners) consists of airbag pyrotechnic or explosive device located in steering wheel and on passenger side of instrument panel, sensors, diagnosis (control/sensor) unit, warning lamp, wiring harness and clockspring (spiral cable). Some models are also equipped with side airbags or SRS system which are built into the driver and passenger front seatbacks. The seat belt pre-tensioner system with load limiter is installed for both the driver seat and the front passenger seat. It operates simultaneously with the SRS airbag system in the event of a frontal accident or impact with an impact exceeding a specified level. When a frontal accident or impact with an impact exceeding a specified level occurs, seat belt slack resulting from clothing or other factors is immediately taken up by the pre-tensioner. automobile passenger is securely restrained. The occupant classification system identifies different size occupants, out of position occupants, and detects if child seat is present in the front passenger seat. The occupant classification system receives inputs from the occupant classification system sensor (located inside the passenger seat cushion assembly) and belt tension sensor (part of the passenger front seat belt assembly and located at the belt anchor location). Depending on classification of passenger, the occupant classification system sends a signal to the airbag diagnosis sensor unit. The airbag diagnosis sensor unit uses this signal to determine deployment or non deployment of the passenger front airbag in the event of a accident or impact. Depending on the signal received, the airbag diagnosis sensor Roof panel (side curtain) airbag pyrotechnic or explosive device are located above the automobile headlining. automobiles with side curtain airbags or SRS system are equipped with labels. ------------------------------------------------------------------------------ INFINITI 1990-2002 THEORY OF OPERATION On 1990-92 models, the Supplemental airbag Restraint System, deploys when right crash zone sensor, center crash zone sensor, left crash zone sensor or tunnel sensor and the safing sensor are simultaneously activated while the ignition switch is in the On position. On 1993-95 models and 1996 G20 models, the Supplemental airbag Restraint System, deploys when the crash zone sensor or tunnel sensor and the safing sensor are simultaneously activated while the ignition switch is in the On position. On 1996-2002 models, the Supplemental airbag Restraint System, deploys if the diagnosis sensor unit activates while the ignition switch is in the ON or START position. On all models, the control unit (diagnostic unit) diagnoses the SRS circuit. When the ignition key is in the ON or START position, the airbag warning lamp will illuminate for approximately 7 seconds, then turn off. This indicates the system is operating normally.The Supplemental Restraint System (SRS) consists of airbag modules located in steering wheel and on passenger side of instrument panel, sensors, diagnosis (control/sensor) unit, warning lamp, wiring harness and spiral cable. G20, J30 & 045 models are also equipped with side airbags which are built into the driver's and passenger's front seats and front seat belt pretensioners. INFINITY 2002-2011 THEORY OF OPERATION The Supplemental airbag Restraint System deploys if the diagnosis sensor unit activates while the ignition switch is in the ON or START position.The control unit (diagnostic unit) diagnoses the SRS circuit. When the ignition key is in the ON or START position, the airbag warning lamp will illuminate for approximately 7 seconds, then turn off. This indicates the system is operating normally. The Supplemental Restraint System (SRS)consists of airbag modules located in steering wheel and on passenger side of instrument panel, sensors, diagnosis (control/sensor) unit, warning lamp, wiring harness and clockspring (spiral cable). FX35/45, G35,135, M45, 045 & 0X56 models are also equipped with side airbags which are built into the driver and passenger front seatbacks. The seat belt pre-tensioner system with load limiter is installed for both the driver seat and the front passenger seat. It operates simultaneously with the SRS airbag system in the event of a frontal collision with an impact exceeding a specified level. When the frontal collision with an impact exceeding a specified level occurs, seat belt slack resulting from clothing or other factors is immediately taken up by the pre-tensioner. Vehicle passengers are securely restrained. The occupant classification system identifies different size occupants, out of position occupants, and detects if child seat is present in the front passenger seat. The occupant classification system receives inputs from the occupant classification system sensor (located inside the passenger seat cushion assembly) and belt tension sensor (part of the passenger front seat belt assembly and located at the belt anchor location). Depending on classification of passenger, the occupant classification system sends a signal to the airbag diagnosis sensor unit. The airbag diagnosis sensor unit uses this signal to determine deployment or non deployment of the passenger front airbag in the event of a collision. Roof panel (side curtain) airbag modules are located above the vehicle headlining. Vehicles with side curtain airbags are equipped with labels.