(9) Reinstall the grab handle onto the headliner.
(Refer to 23 - BODY/INTERIOR/ASSIST HANDLE -
INSTALLATION).
(10) Reinstall the trim onto the inside of the B-pil-
lar. (Refer to 23 - BODY/INTERIOR/B-PILLAR TRIM
- INSTALLATION).
(11) Reinstall the pinch welt to the front door
opening (Fig. 44).
(12) Do not reconnect the battery negative cable at
this time. The supplemental restraint system verifi-
cation test procedure should be performed following
service of any supplemental restraint system compo-
nent. (Refer to 8 - ELECTRICAL/RESTRAINTS -
STANDARD PROCEDURE - VERIFICATION TEST).
SIDE IMPACT SENSOR
DESCRIPTION
On vehicles equipped with the optional side curtain
airbags, two side impact sensors are used, one each
for the left and right sides of the vehicle (Fig. 51).
These sensors are mounted remotely from the bi-di-
rectional safing sensor that is internal to the Airbag
Control Module (ACM). The side impact sensors are
each secured with two screws to the forward vertical
surface of the right and left front door step wells and
concealed behind the step well trim paneling within
the passenger compartment.
The impact sensor housing has an integral connec-
tor receptacle and two integral mounting flanges, one
at the top and one at the bottom. An arrow on the
sensor housing provides a visual verification of the
proper orientation of the unit, and should always be
pointed toward the outboard side of the vehicle. A
cavity in the center of the molded plastic impact sen-
sor housing contains the electronic circuitry of the
sensor, which includes an electronic communication
chip and an electronic impact sensor. Potting mate-
rial fills the cavity to seal and protect the internal
electronic circuitry and components. The side impact
sensors are each connected to the vehicle electrical
system through a dedicated take out and connector of
the vehicle wire harness.
The side impact sensors cannot be repaired or
adjusted and, if damaged or faulty, they must be
replaced.
OPERATION
The side impact sensors are electronic accelerome-
ters that sense the rate of vehicle deceleration, which
provides verification of the direction and severity of
an impact. Each sensor also contains an electronic
communication chip that allows the unit to commu-
nicate the sensor status as well as sensor fault infor-
mation to the microprocessor in the Airbag Control
Module (ACM). The ACM microprocessor continu-
ously monitors all of the passive restraint system
electrical circuits to determine the system readiness.
If the ACM detects a monitored system fault, it sets
a Diagnostic Trouble Code (DTC) and controls the
airbag indicator operation accordingly.
The impact sensors each receive battery current
and ground through dedicated left and right sensor
plus and minus circuits from the ACM. The impact
sensors and the ACM communicate by modulating
the voltage in the sensor plus circuit. The hard wired
circuits between the side impact sensors and the
ACM may be diagnosed and tested using conven-
tional diagnostic tools and procedures. However, con-
ventional
diagnostic
methods
will
not
prove
conclusive in the diagnosis of the ACM or the impact
sensors. The most reliable, efficient, and accurate
means to diagnose the impact sensors, the ACM, and
the electronic message communication between the
sensors and the ACM requires the use of a diagnostic
scan tool. Refer to the appropriate diagnostic infor-
mation.
Fig. 51 Side Impact Sensor
1 - MOUNTING FLANGE (2)
2 - IMPACT SENSOR
3 - CONNECTOR RECEPTACLE
VA
RESTRAINTS
8O - 39