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7 - 9
FI
FUEL INJECTION SYSTEM
Fault code table
Fault
Code No.
Symptom
Probable cause of malfunction
Diagnostic code
12
No normal signals are received from
the crankshaft position sensor.
• Open or short circuit in wiring harness.
• Defective crankshaft position sensor.
• Malfunction in pickup rotor.
• Malfunction in ECU.
• Improperly installed sensor.
—
13
Intake air pressure sensor-open or
short circuit detected.
• Open or short circuit in wiring sub lead.
• Open or short circuit in wiring harness.
• Defective intake air pressure sensor.
• Malfunction in ECU.
03
14
Faulty intake air pressure sensor pipe
system
• disconnected hose
• clogged hose
• Intake air pressure sensor hose is disconnected,
clogged, kinked, or pinched.
• Malfunction in ECU.
03
15
Throttle position sensor-open or short
circuit detected.
• Open or short circuit in wiring sub lead.
• Open or short circuit in wiring harness.
• Defective throttle position sensor.
• Malfunction in ECU.
• Improperly installed throttle position sensor.
01
16
A stuck throttle position sensor is
detected.
• Stuck throttle position sensor.
• Malfunction in ECU.
01
19
Open circuit in the input line (blue/yel-
low lead) of ECU is detected when
the start switch is pressed.
• Open circuit in wiring harness (ECU coupler).
• Malfunction in ECU.
20
21
Coolant temperature sensor-open or
short circuit detected.
• Open or short circuit in wiring harness.
• Defective coolant temperature sensor.
• Malfunction in ECU.
• Improperly installed sensor.
06
22
Intake air temperature sensor-open or
short circuit detected.
• Open or short circuit in wiring harness.
• Defective intake temperature sensor.
• Malfunction in ECU.
• Improperly installed sensor.
05
30
The scooter has overturned.
• Overturned.
• Malfunction in ECU.
08
33
Open circuit is detected in the primary
lead of the ignition coil.
• Open circuit in wiring harness.
• Malfunction in ignition coil.
• Malfunction in ECU.
• Malfunction in a component of ignition cut-off circuit sys-
tem.
30
37
The ISC (idle speed control) valve is
stuck fully open.
• Defective speed sensor.
• Malfunction in throttle body.
• Malfunction in throttle cables.
• ISC (idle speed control) valve is stuck fully open.
• Malfunction in ECU.
54
39
Fuel injector open or short circuit is
detected.
• Open or short circuit in wiring harness.
• Defective fuel injector.
• Malfunction in ECU.
36
41
Lean angle cut-off switch-open or
short circuit detected.
• Open or short circuit in wiring harness.
• Defective lean angle cut-off switch.
• Malfunction in ECU.
08
42
No normal signals are received from
the speed sensor.
• Open or short circuit in wiring harness.
• Defective speed sensor.
• Malfunction in vehicle speed sensor detected unit.
• Malfunction in ECU.
07
43
Supply power to the fuel injector and
fuel pump is not normal.
• Open circuit in wiring harness. (red or red/blue lead)
• Malfunction in ECU.
09
Summary of Contents for 2004 YP400
Page 1: ...2004 YP400 S 5RU1 AE1 SERVICE MANUAL ...
Page 2: ......
Page 8: ......
Page 9: ...GEN INFO 1 ...
Page 11: ...GEN INFO ...
Page 28: ...SPEC 2 ...
Page 30: ...SPEC ...
Page 77: ...CHK ADJ 3 ...
Page 137: ......
Page 138: ...CHAS 4 ...
Page 210: ......
Page 211: ...ENG 5 ...
Page 286: ...COOL 6 ...
Page 288: ...COOL ...
Page 299: ...FI 7 ...
Page 301: ...FI ...
Page 342: ...ELEC 8 ...
Page 378: ...8 34 ELEC LIGHTING SYSTEM ...
Page 404: ......
Page 405: ...TRBL SHTG 9 ...
Page 415: ......
Page 416: ...YAMAHA MOTOR CO LTD 2500 SHINGAI IWATA SHIZUOKA JAPAN ...