LaCrosse V6-3.8L VIN 2 (2005)
Air Bag: Description and Operation
Inflatable Restraint Passenger Presence System
INFLATABLE RESTRAINT PASSENGER PRESENCE SYSTEM
IMPORTANT: The passenger presence system (PPS), heated seat element (if equipped), and the seat bottom foam cushion is a calibrated unit and
cannot be service separately. After repairing or replacing the PPS, the system must be rezeroed in order to function properly.
The PPS is used to monitor the weight of an occupant on the front outboard passenger seat and communicate the status to the sensing and diagnostic
module (SDM) whether to enable or suppress the deployment of the instrument panel (I/P) inflator module. The PPS consist of an electronic control
module, sensor mat, heated seat element (if equipped), wiring harness, and PASSENGER AIR BAG ON/OFF indicators. The sensor is made up of
several flexible conductive metal strips placed underneath the seat cushion trim. These sensor strips transmit and receive a low-level electric field. The
weight of the occupant sitting in the front passenger seat is measured as a change in current flow within the sensor mat. If the sensor determines that the
occupant weight is less than a specified value, the PPS module will send a suppress signal to the SDM to disable the I/P module. If the sensor determines
the occupant weight is higher than a specified value, the PPS module will send an enable signal to the SDM to enable the I/P. The PPS module will
notify the customer of the enable/disable status by turning on one of the PASSENGER AIR BAG ON/OFF indicators located in the center of the
instrument panel cluster (IPC). The PPS monitors itself for faults and will display flash diagnostic trouble codes (DTCs) when a fault is detected and the
SDM commands it by using the PASSENGER AIR BAG ON/OFF indicators. The PPS will also notify the SDM of a fault and the SDM will request the
IPC to turn the AIR BAG indicator located on the IPC ON. To determine what DTCs have been set by the PPS, the scan tool is used to command the
SDM to request the PPS to flash the DTCs using the PASSENGER AIR BAG ON/OFF indicators located on the I/P.
