FUEL SUPPLY
Fuel cut-out on impact
13
AIM
The aim of this function is to avoid a fire after an
accident due to a fuel leak. To accomplish this, all
components which pump fuel from the fuel tank
are stopped during and after the impact. They
may only be started again by a mechanical action
performed by the driver or repair mechanic.
DESCRIPTION
The system comprises an inertia switch which may
be reset, which:
- detects the impact (1),
- cuts the electrical circuit.
99511R
It is mounted:
• For petrol engines, between track 1 of the
pump relay (236) and the + feed.• For diesel engines, between the + feed and
the fuel shut off (or the coded solenoid valve
if the vehicle is fitted with an engine
immobiliser).
OPERATION
During the impact, the inertia switch ball leaves its
seat and breaks the electrical current.
For petrol engines, the + feed to the pump relay
control circuit (236) is cut. The pump and the
injectors are thus no longer fed electrically.
The fuel in the fuel tank is therefore isolated.
For diesel engines, the + feed to the fuel shut off
or the coded solenoid valve is cut.
The pump can no longer take up fuel, there is no
high pressure any more. Any risk of fire due to
high pressure diesel spray over the engine is
removed.
RESETTING THE SWITCH AND SWITCH
OPERATION
To reset the inertia switch, press the top to
reposition the ball in its seat.
IMPORTANT:
• for petrol engines, after resetting the switch,
the computer memory
MUST be erased using
the XR25. The injection computer will
memorise a pump relay fault when the system
is triggered.
• for diesel engines, after resetting the switch,
the passenger compartment connection unit
memory
MUST be erased using the XR25. This
unit will memorise a break in feed to the
coded solenoid valve.
13-1
