Yamaha YP400T, YP400V, YP400W Service Manual page 298

Fault code table
Fault
Symptom
Code No.
No normal signals are received from
the crankshaft position sensor.
12
Intake air pressure sensor-open or
short circuit detected.
13
Faulty intake air pressure sensor pipe
system
14
• disconnected hose
• clogged hose
Throttle position sensor-open or short
circuit detected.
15
A stuck throttle position sensor is
16
detected.
Open circuit in the input line (blue/yel-
19 low lead) of ECU is detected when
the start switch is pressed.
Coolant temperature sensor-open or
short circuit detected.
21
Intake air temperature sensor-open or
short circuit detected.
22
The scooter has overturned.
30
Open circuit is detected in the primary
lead of the ignition coil.
33
The ISC (idle speed control) valve is
stuck fully open.
37
Fuel injector open or short circuit is
39 detected.
Lean angle cut-off switch-open or
41 short circuit detected.
No normal signals are received from
the speed sensor.
42
Supply power to the fuel injector and
43
fuel pump is not normal.
FUEL INJECTION SYSTEM
Probable cause of malfunction
• Open or short circuit in wiring harness.
• Defective crankshaft position sensor.
• Malfunction in pickup rotor.
• Malfunction in ECU.
• Improperly installed sensor.
• Open or short circuit in wiring sub lead.
• Open or short circuit in wiring harness.
• Defective intake air pressure sensor.
• Malfunction in ECU.
• Intake air pressure sensor hose is disconnected,
clogged, kinked, or pinched.
• Malfunction in ECU.
• 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.
• Stuck throttle position sensor.
• Malfunction in ECU.
• Open circuit in wiring harness (ECU coupler).
• Malfunction in ECU.
• Open or short circuit in wiring harness.
• Defective coolant temperature sensor.
• Malfunction in ECU.
• Improperly installed sensor.
• Open or short circuit in wiring harness.
• Defective intake temperature sensor.
• Malfunction in ECU.
• Improperly installed sensor.
• Overturned.
• Malfunction in ECU.
• Open circuit in wiring harness.
• Malfunction in ignition coil.
• Malfunction in ECU.
• Malfunction in a component of ignition cut-off circuit sys-
tem.
• Defective speed sensor.
• Malfunction in throttle body.
• Malfunction in throttle cables.
• ISC (idle speed control) valve is stuck fully open.
• Malfunction in ECU.
• Open or short circuit in wiring harness.
• Defective fuel injector.
• Malfunction in ECU.
• Open or short circuit in wiring harness.
• Defective lean angle cut-off switch.
• Malfunction in ECU.
• Open or short circuit in wiring harness.
• Defective speed sensor.
• Malfunction in vehicle speed sensor detected unit.
• Malfunction in ECU.
• Open circuit in wiring harness. (red or red/blue lead)
• Malfunction in ECU.
7 - 9
FI
Diagnostic code
—
03
03
01
01
20
06
05
08
30
54
36
08
07
09