Can-Am DS 450 2008, Shop Manual

Page: 201 / 401

Section 05 FUEL SYSTEM
Subsection 01 (ELECTRONIC FUEL INJECTION (EFI))

WARNING
Fuel lines remain under pressure at all times.
Always proceed with care and use appropri-
ate safety equipment when working on pres-
surized fuel system.
Wear safety glasses.
Proceed with care when removing/installing
pressure test equipment or disconnecting
fuel line connections.
Use the B.U.D.S.
software to release fuel pressure prior to
removing a hose. Cover the fuel line con-
nection with an absorbent shop rag. Slowly
disconnect the fuel hose to minimize spilling.
Wipe off any fuel spillage in the engine com-
partment. Do not allow fuel to spill on hot
engine parts and/or on electrical connectors.
Never use a hose pincher on injection system
high pressure hoses. Replace any damaged
or deteriorated fuel lines.

WARNING
Always perform the fuel pressure test if any
component has been removed. A pressure
test must be done before turning the igni-
tion key to ON and setting the engine stop
switch to RUN. The fuel pump is activated
each time in these conditions. After perform-
ing a fuel pressure test, use the valve on the
fuel pressure gauge to release the pressure (if
so equipped).
Electrical System
It is important to check that the electrical system
is functioning properly:
– Battery
– Fuses
– Relay(s)
– Ground connections
– Wiring connectors.
Never use a battery charger to substitute tem-
porarily the battery as it may cause the ECM (en-
gine control module) to work erratically or not to
work at all.
Ensure that all electronic components are gen-
uine. Any modification on the wiring harness may
lead to generate fault codes or bad operation.
NOTE: For diagnostics purposes, use B.U.D.S.
software. See
MONITORING SYSTEM/FAULT
CODES
subsection.
Check related-circuit fuse solidity and condition
with an ohmmeter. Visual inspection could lead
to false results.
After a problem has been solved, ensure to
clear the fault code(s) in the ECM using the
B.U.D.S.
software. Refer to
MONITORING
SYSTEM/FAULT CODES
subsection.

WARNING
Some EMS components are continuously
powered by the battery when ignition key
is turned on and engine stop switch is set
in RUN position. The ECM switches the cir-
cuit to the ground to complete the electrical
circuits it controls. Take this into account
when troubleshooting.
Always disconnect
the battery prior to disconnecting any electric
or electronic parts.
Electrical Connectors
Pay particular attention to ensure that pins are not
out of their connectors or out of shape.
Make sure terminals are properly crimped on
wires and fastened in housing, and that they are
free of corrosion or moisture.
When probing terminals, pay attention not to bend
the terminal as this could bring a loose connection
that would be difficult to troubleshoot.
Pay attention to the following:
– ECM connectors:
Do not apply dielectric
grease or any other lubricant.
– Other connectors: Apply a silicon-based dielec-
tric grease or other appropriate lubricant.
Resistance Measurement
When measuring the resistance with an ohmme-
ter, all values are given for a temperature of 20°C
(68°F). The resistance value of a resistance varies
with the temperature. The resistance value for
usual resistor or windings (such as injectors)
in-
creases as the temperature increases. However,
our temperature sensors are NTC types (Negative
Temperature Coefficient) and work the opposite
which means that the resistance value
decreases
as the temperature increases. Take it into account
when measuring at temperatures different from
20°C (68°F). Use the proper table for resistance
variation relative to temperature for
temperature
sensors. See the specific sensor.
The resistance value of a temperature sensor may
test good at a certain temperature but it might be
defective at other temperatures. If in doubt, try a
new sensor.
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