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Brief description, PPS

Brief description, PPS

Overview



• Control module, PPS (591), under right-hand front passenger seat

• Silicone filled seat mat with pressure sensor (642), in right-hand front passenger seat

• Belt force sensor (643), is secured in the belt anchorage point in the floor.

• Indicator lamp, passenger airbag ON/OFF in the AC panel.


Description

PPS (Passenger presence system) is a part of the airbag system. The function of PPS is to detect whether an adult or child is sitting on the passenger side. If the seat is empty, or if a child is in the seat, then the airbag's control module is informed of this, which then switches off the passenger airbag and side airbag.

Background

The USA has introduced a new legal requirement that regulates when a passenger airbag/side airbag should or should not be activated. This legal requirement is named FMVSS 208. PPS is a system that shall switch off the passenger airbag/side airbag for all passengers up to 6 years old (23.4 kg) and activate the passenger airbag/side airbag for passengers who weigh more than 46.7 kg or more, in accordance with the legal requirement. In the grey area between 23.4 kg and 46.7 kg the decision to activate/deactivate passenger airbag/side airbag is correct either way in accordance with the legal requirement.

Equipment

The PPS system components consist of a silicone filled seat mat connected to a pressure sensor, a force sensor for measuring seatbelt loading and two indicator LEDs, passenger airbag/side airbag ON or OFF.

Location

The PPS system control module is located on the underside of the passenger seat. A mat, containing the silicone filled seat mat and pressure sensor, is fitted on the seat and the belt force sensor (643) on the belt anchorage point. The two indicator lamps ON/OFF are located in the ACC panel.

Checking and activation

The PPS system control module detects whether:


• a passenger is sitting in the passenger seat. The PPS control module converts the pressure into weight by means of a pressure sensor.

• a child seat is connected to the seatbelt. The weight is calculated using the belt force sensor if the tensioning force of the seat then affects the total weight.


Based on this information the PPS control module illuminates one of the two indicator lamps depending on whether or not the passenger airbag/side airbag is active. Diagnosis and status are sent via a communication cable to the airbag's control module (ACM) which connects or disconnects the passenger airbag/side airbag.

When a fault occurs the passenger airbag/side airbag is disconnected.