8
FIAT PUNTO NATURAL POWER
PIPING
The methane piping from the filler to the
pressure regulator/reduction unit is made
from galvanized steel and covered in plas-
tic (high pressure) and is located outside
the passenger compartment; the piping
from the pressure regulator/reduction
unit to the methane injectors is in stain-
less steel.
PRESSURE
REGULATOR/
REDUCTION UNIT
The pressure reduction unit Fig. 8is in-
stalled in the engine compartment.
It has the task of reducing the pressure
of the methane from the value in the can-
ister to the supply value for the methane
injectors (about 6 bar) and keeping it con-
stant in all operating conditions.
METHANE INJECTORS
There are 4 dedicated injectors for the
methane gas A-Fig. 9, fitted on the intake
manifold near the cylinder head, one for
each intake duct; they are supplied at a
constant pressure (about 6 bar) and op-
erated by the electronic control unit.
OIL SEPARATOR FILTER
The oil separator filter Fig. 10is installed
in the engine compartment.
It has the task of separating the excess oil
in the methane.
PETROL/
METHANE SWITCH
This engine normally runs on methane ex-
cept during starting when it runs on
petrol. Switching to methane takes place
automatically and is shown on the instru-
ment panel display by the Ksignal in the
display going out fig. 12.
fig. 9F0M0458m
fig. 8F0M0457m
fig. 10F0M0459m
603_97_125 Punto Nat P GB 1ed 6-05-2009 10:14 Pagina 8
9
FIAT PUNTO NATURAL POWER
The four vertical bars near the letters
CNG in the instrument panel display Figs.
12a-12bindicate the level of methane in
the canisters.
When the residual amount of methane
goes below 1/5 of the capacity of the can-
isters, the CNG logo and the lowest lev-
el Fig. 13flash to indicate the reserve and
notify the need to refuel.
If the methane has run out, switching to
petrol takes place automatically: the Kin-
dicator near the CNG symbol Figs. 12a-
12blights up in the instrument panel dis-
play.
If you particularly want the car to run on
petrol, press button A - Fig. 11located
between the controls in the dashboard.
The LED in the button coming on means
that the request to switch has taken place
correctly.
fig. 11F0M0460m
fig. 12bF0M0471m
fig. 13F0M0462m
fig. 12aF0M0461m
If the last fuel system in use
was petrol, when starting the
switch to methane should be
requested manually by the
customer.
The actual change to the chosen fuel sys-
tem takes place depending on the vehicle
usage conditions to guarantee switching in
absolute safety and will be confirmed by
the Kwarning light in the instrument pan-
el display coming on/going off.
The manual selection of the op-
erating mode from petrol to
methane and viceversa is only ac-
tivated if the engine speed is be-
low 2000 rpm.
At the time of the switching
request there will be a metal-
lic noise coming from the valves to
pressurize the circuit (more obvious
with the ignition in the MAR position).
As a result of the switching logics de-
scribed above, it is entirely normal for
there to be a delay between the tick-
ing of the valve and the switching off
at the instrument panel.
WARNING
603_97_125 Punto Nat P GB 1ed 6-05-2009 10:14 Pagina 9
10
FIAT PUNTO NATURAL POWER
Do not switch between the
two operating modes whilst
starting the engine
WARNING
In addition, in the case of starting at out-
side temperatures of below around -10°C,
the switching times from Petrol to
Methane increase to allow the pressure
regulator/reduction unit to become warm
enough.
IMPORTANT If the switching takes place
during acceleration or pick-up, there may
be a brief flat spot (fall in power).With the reconfigurable multifunction dis-
play, any system failure is signalled by the
dedicated message and, at the same time,
by the
Rsymbol coming on and the four
methane levels going out. In this case, go
to a Fiat Dealership as quickly as possi-
ble.
STARTING
THE ENGINE
To carry out the starting manoeuvre, see
the warnings and advice in the Owner
Handbook under the chapter “Starting the
engine”.
PROTECTIVE FUSES
The table below contains a list of the pro-
tective fuses with reference to the
petrol/methane version. For all the other
fuses, consult the Owner Handbook that
this supplement comes with.
If the methane has run out, the control
unit automatically manages the switch to
running on petrol.
Engine compartment junction unit
CONSUMERS FUSE AMPS
Control systemprimary loads
(coils and injectors)
Methane system
CNG system management solenoid valves 22
8415
10 SYSTEM FAILURE SIGNALLING
With the multifunction display, any system
failure is signalled through a dedicated
messages and, at the same time, by the
CNG logo and the four methane levels
flashing (with solid bars). In this case, go
to a Fiat Dealership as quickly as possi-
ble.
603_97_125 Punto Nat P GB 1ed 6-05-2009 10:14 Pagina 10
