K 1500 Truck 4WD V8-4.8L VIN V (2003)
Seat Occupant Sensor: Description and Operation
Inflatable Restraint Passenger Presence System (PPS)
The passenger presence system (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 I/P module. The PPS consist of an electronic control
module, silicone filled sensor pad, pressure sensor, seat belt tension retractor sensor, I/P module disable switch, wiring harness, and PASSENGER AIR
BAG ON/OFF indicators. The silicone filled sensor pad is located under the passenger seat foam cushion and is connected by a hose clamped to the
pressure sensor. The weight of the occupant sitting in the front passenger seat is measured as a pressure change within the bladder by the pressure sensor.
The pressure sensor sends a voltage signal to the PPS module. If the pressure from the occupant's 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 pressure from the occupant's weight is higher than a specified value, the PPS
module will send an enable signal to the SDM to enable the I/P module. 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 on the rear view mirror. The PPS monitors itself for faults and will set flash
diagnostic trouble codes (DTCs) if a fault is detected. The PPS will also notify the SDM of a fault and the SDM will request the instrument panel cluster
to turn ON the AIR BAG indicator located on the instrument panel cluster (IPC). To determine what DTCs have been set by the PPS, the Tech 2 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 rear view mirror.
IMPORTANT: The passenger presence system (PPS) is a calibrated unit. When replacing the assembly all parts in the service kit must remain
together. Do not mix any of the old parts with the new parts. After repairing or replacing the PPS, the system must be rezeroed in order to function
properly.
