DESCRIPTION AND OPERATION
4.52 RANGE ROVER
Seat Belt Pre-tensioners
If the SRS DCU detects a front or rear impact, it will deploy the front seat belt pre-tensioners.
The SRS DCU (C0256) provides a firing signal to the RH seat belt pre-tensioner (C0252) on
a UN wire. An earth path is provided by the SRS DCU (C0256) on a UR wire. The SRS DCU
(C0256) provides a firing signal to the LH seat belt pre-tensioner (C0254) on a YR wire. An
earth path is provided by the SRS DCU (C0256) on a YN wire.
Battery Disconnection
In the event of an impact severe enough to implement stage 2 airbag deployment, a
pyrotechnic charge on the positive battery terminal will disconnect the battery. The SRS
DCU (C0256) provides a firing signal to the battery (C2250) on an NR then B wire. An earth
path is provided by the SRS DCU (C0256) on a B then N wire.
Body Control Unit (BCU)
In the event of an impact severe enough to trigger the SRS system, the SRS DCU (C0256)
provides a pulsed voltage signal to the BCU (C0661) on an SU wire. The BCU then enters
its 'crash' mode, unlocking all the doors, illuminating the interior lamps, and powering the
hazard warning lamps.
SRS Warning Lamp
The SRS DCU (C0256) controls operation of the SRS warning lamp (C0230) by providing a
pulsed voltage feed on an NP wire.
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