Envoy 2WD V8-5.3L VIN P (2004)
Impact Sensor: Description and Operation
Inflatable Restraint Side Impact Sensor (SIS)
INFLATABLE RESTRAINT SIDE IMPACT SENSOR (SIS)
The side impact sensor (SIS) contains a sensing device (accelerometer) which monitors vehicle acceleration and velocity changes to detect side collisions
that are severe enough to warrant air bag deployment. The SIS is not part of the deployment loop, but instead provides an input to the SDM. The SDM
contains a microprocessor that performs calculations using the measured accelerations and compares these calculations to a value stored in memory.
When the generated calculations exceed the stored value, the SDM will cause current to flow through the deployment loops deploying the side air bags.
