YG125-30A Maintenance Manual
Engine management system
149
ITEM
PIN No.
DESCRIBE
ITEM
PIN No.
DESCRIBE
1
J1-1
IACAHi
1
J2-1
COILA
2
J1-2
MAGNETO CUT RELAY
2
J2-2
GND
3
J1-3
MIL
3
J2-3
KW2000
4
J1-4
4
J2-4
CRANK HI
5
J1-5
5
J2-5
INJA
6
J1-6
TACH
6
J2-6
7
J1-7
CANLo
7
J2-7
O2AHTR
8
J1-8
CANHi
8
J2-8
IAT_MAT
9
J1-9
GND
9
J2-9
FUEL PUMP RELAY
10
J1-10
10
J2-10
5VRTN
11
J1-11
IACALo
11
J2-11
MAP
12
J1-12
IACBHi
12
J2-12
TPS
13
J1-13
IACBLo
13
J2-13
CRANK LO
14
J1-14
14
J2-14
CLT
15
J1-15
15
J2-15
IGN
16
J1-16
DIAG
16
J2-16
5VREF
17
J1-17
FUEL PUMP RECIRCULATION
17
J2-17
O2A
18
J1-18
PNSW
18
J2-18
VBATT
Maintenance of Engine management system
Because of the EFI, there are many possibilities for the engine issues. In other word, one issue may be caused by the
mechanical problem or the EFI components. And the diagnostic tools cannot 100% indicate the root cause. So this
manual shows the way to dig out the root cause with the help of the diagnostic tools.
Maintenance matters needing attention
1) Do not disassemble the components arbitrarily. It may damage the components if the warter or the oil seep into the
parts.
2) Turn the ignition off, before connect or disconnect the connectors.
3) Make sure the temperature of the ECU is below 80
℃
.
4) The fuel pressure is much high ( about 250kPa), so please do not disassemble the fuel pipe arbitrariliy. If have to,
pleae release the pressure at first, and make sure the operation is dilivered in the ventilated environment by the the
professional mantenance persons.
5) When disassmeble the fuel pump from the pump, make sure the power is off. Or it may casue the fire.
6) The fuel pump cannot work in air or water, it will shorten the service life. And the positive and negative connecters
cannot be exchanged.
7) The ignition system check only could be delivered when it is nessasary. When check the spark plug out of the
engine, if start the engine, please make sure the throttle is closed. Or too much unburned gasoline coming to the catalyst
may damage the catalyst.
8) The idle speed is adjusted by the ECU. The idle pintle is not alowed to adjust.
9) The Positive and Negative of the battery cannot be reversed. It may damage the EFI components.
10) It is forbidden to remove the battery when the eninge is running.
11) Cannot messure the signal by pierce the harness.
Tools
1)
Multimeter: messure the voltage, the resistance and the harness connection.
2)
Diagnostic tool: reading the malfcode, and engine parameters.
3)
Oil pressure garge: messure the fuel pressure.
4)
Cylinder pressure garge: messure the pressure garge.
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