L322 Range Rover System Description and Operation
RESTRAINT SYSTEMS
DESCRIPTION AND OPERATION
75-15
Battery Disconnect Unit
The battery disconnect unit is attached to the positive terminal on the battery and allows the DCU to disconnect the
main starter cable during a crash.
The battery disconnect unit incorporates the positive terminal connector and heavy duty cables for the starter and for
engine and passenger compartment power distribution. The starter cable connection is contained in a plastic housing
next to the battery terminal. The end fitting of the starter cable is a tapered press fit in one end of a gas discharge
tube. The other end of the gas discharge tube contains a gas generator and a squib connected to the DCU.
When the DCU fires the squib, the gas from the gas generator forces the end fitting of the starter cable out of the gas
discharge tube and breaks the connection with the starter motor. As the end fitting is pushed out of the gas discharge
tube, spring tabs in the plastic housing engage with the rim of the end fitting to hold it clear of the gas discharge tube.
The fuel pump motor is shut off by the relevant ECM after the ECM receives a crash signal from the SRS DCU. See
relevant engine management sections for more detail.
1 Battery terminal connector
2 Electrical connector
3 Gas generator
4 Gas discharge tube
5 Spring tab
6 Starter cable
7 Power distribution cable
8 View after firing
M76 4543
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