module (SDM) to request the enabling or disabling of the I/P module. The occupants are notified of the
enabling or disabling of the I/P module via the I/P module disable switch ON/OFF indicator located in the I/P
module disable switch.
Inflatable Restraint I/P Module Disable Switch Indicator
The instrument panel (I/P) module disable switch ON/OFF indicator is an LED located in a position that can be
viewed by the occupants in the front seats. The location varies depending on the vehicle. When the I/P module
disable switch is in the disable position, the I/P module disable switch indicator illuminates. When the I/P
module disable switch is in the enable position, the I/P module disable switch indicator is not illuminated. The
I/P module disable switch indicator will dim to a lower intensity when the headlamp switch is turned ON.
Inflatable Restraint Wiring Harnesses
The inflatable restraint wiring harnesses connect the sensing and diagnostic module (SDM), inflator modules,
passenger presence system (PPS), electronic frontal sensors (EFS), seat position switches (SPS), passenger seat
belt tension retractor sensor, and the class 2 serial data circuit together using weather pack connectors. SIR
deployment loop connectors are yellow in color for easy identification. When repairing SIR system wiring
harnesses, follow the proper testing and wiring repair procedures outlined in this manual.
Steering Wheel and Column
The steering wheel and column are designed to absorb energy when driver contact is made with the steering
wheel or inflated air bag. In a frontal collision the driver may contact the steering wheel directly or load the
steering wheel and column through the inflated air bag. When the driver applies load to the air bag or steering
wheel the column will compress downward absorbing some of the impact, helping to reduce bodily injuries to
the driver. The steering wheel and column must be inspected for damage after a collision.
Driver and Passenger Knee Bolsters
The knee bolsters are designed to help restrain the lower torsos of front seat occupants by absorbing energy
through the front seat occupants' upper legs. In a frontal collision the front seat occupants legs may come in
contact with the knee bolsters. The knee bolsters are designed to crush or deform absorbing some of the impact,
which helps to reduce bodily injuries. The driver and passenger knee bolsters are located in the lower part of the
instrument panel and must be inspected for damage after a collision.
SPECIAL TOOLS AND EQUIPMENT
SPECIAL TOOLS
Special Tools
Illustration
Tool Number/Description
2004 Hummer H2
2004 RESTRAINTS SIR - Hummer H2