XK-8 Convertible (X100) V8-4.0L (AJ26) (1997)
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Impact Sensor: Description and Operation
Control Module
The control module is fitted behind the fascia, by the A-post on the right side of the car. The module has diagnostic ability, with the safing sensor built
into the module and not, as previously, a separately mounted unit. The control module includes an internal battery backup power supply enabling
airbag deployment in a crash situation even if the main battery cable is disconnected/broken by the impact.
Impact Sensors
Two primary crash sensors are fitted on the vehicle front upper cross member, in front of the radiator, inboard of the headlamps. These crash sensors
are hardwired to the airbags. At least one of the crash sensors must be made, along with the safing sensor, for airbags to deploy. A disarm feature is
incorporated in the control module that removes all deployment power from the airbag/SRS without the closure of a primary sensor.
System Management
The SRS Module continuously monitors all airbag/SRS system components and wiring connections for faults. If a system fault occurs a fault code is
written into the modules's nonvolatile memory and a warning is displayed on a continuous indicator LED. If the airbag/SRS readiness indicator line
has a fault and another fault in the system is detected, an audible tone will be heard, five sets of five bleeps. The readiness indicator line fault must be
corrected before fault codes can be determined.
Fault codes can still be read through the ISO connector, even if the readiness line is functional or not. If a fault exists that makes unwanted airbag/SRS
deployment possible, the control unit will attempt to remove deployment power by turning on a solid state switch to rupture the 1OA battery fuse.
WARNING: Do not substitute another fuse value for the 1OA battery fuse. This may cause disarming failure. Do not attempt to replace the
10A battery fuse until the airbag/SRS system has first been deactivated. The fuse is located in the Driver Side Fascia Fusebox - Fuse F4
The module will not rupture the fuse a second time thus allowing the fault to be rectified and cleared.
