Sym HD2 125 Service Manual page 89

5. Fuel Injection System
Fuel Pump
Fuel unit
G
Y/W
Fuel pump & fuel unit coupler plan
Confirmed working voltage
Fuel pump
Fuel unit
G
B/O
Harness-face coupler plan
Resistance Confirmation
5-26
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Functional Description:
Powered by DC 8~16V, and has four-pin socket on the pump.
The two terminals are connected to power source and ground
respective. The ECU is to control and manage the operation of fuel
pump through electrical power.
Its major component is a driving fan pump that equipped with a low
electrical consuming DC motor. Powered by 12V voltage and keep
fuel pressure inside the fuel pump in 294±6kpa (about 3 kg / cm
The fuel pump is located inside of the fuel tank, and installed a filter in
front of its inlet so that can prevent from foreign materials sucking into
the fuel pump to damage it and the fuel injector.
Fuel
pump
Testing Procedures 1:
G
Fuel pump working voltage confirmed:
Fuel pump coupler to properly (using the probe tool), or can be
●
B/O
removed coupler working voltage measurements (direct
measurement).
Open the main switch, but not to start engine.
●
Use "volteg meter" DC stalls (DCV) to check fuel pump voltage.
●
Confirmed working voltage:
●
Volteg meter negative access to the wire harness fuel pump coupler
2nd pin (Green).
Voltage meter positive access to the wire harness fuel pump coupler
first pin (Black / Orange).
Cautions
Conducting fuel pump voltage measurement, if the main switch to
●
open three seconds after the engine did not started, the ECU will
automatically cut off the fuel pump power supply.
Detection judge 1:
1. Working voltage value:
2. Resistance value:
3. Fuel pressure:
G
Testing Procedures 2:
Resistance Confirmation:
Y/W
Removed coupler on the fuel pump.
●
Use of the "meter"
●
White & Green).
Detection judge 2:
Fuel unit resistance value:
●
Above 10V
1.5±0.5Ω
294±6kPa (about 3kg/cm
Ohm stalls, Measurement fuel unit resistance (Yellow /
4~107.5Ω
2
)
2
).