Other models contain a Supplemental Inflatable Restraint (SIR) System, air bag that in the event of head-on or frontal collision will protect the driver and the person seated close to him. It shall comprise an airbag module in the steering wheel and the instrument panel; two crash sensors in front; a diagnostic monitor with a backup power supply in the passenger compartment. On the 2010 and later models, front side impact optioned airbags are located at the top of the front seats. This is an airbag inflator module installed on a steering wheel, which has a cushion and inflater unit and inflates the bag almost immediately an electrical stimulus is received. Another airbag is the passenger airbag, positioned where the glove compartment is situated and it is much bigger than the steering wheel unit and also works under the same principle of inflation. The restraint control module is responsible for checking the airbag system and such check is performed every time the car is started, in the process an indicator comes on to show that everything is well or not well depending on the situation. If the light stays on or is not on at all then there is an underlying problem which can only be diagnosed by a technician. Extreme care must be taken when working around areas close to the SRS system since electrical test equipment can deployment of airbags. The initial models fit three sensors as known, but the latter versions have four sensors all of which transmit signals to the electronic diagnostic monitor to inflate the airbags in sufficient impacts. The monitor charges the airbag system from the power supply irrespective of the battery and scans the system when the vehicle starts. It is very important to disable the system before working near the airbag concerned and the procedures for it varies for 2005 and earlier models and 2006 and later models. There is an airbag shut off on models with a passenger airbag where you can disable it when you are carrying a rear-facing child seat. The checking of the function of the airbag warning light entails testing of the SRS system, with any anomaly meaning that the vehicle must undergo check at the dealership.