FUEL INJECTION SYSTEM
8-39
Fault code No. 46
Fault code No.
46
Item
Vehicle system power supply: normal voltage is not supplied to the
ECU.
Fail-safe system
Able/Unable to start engine
Able/Unable to drive vehicle
Diagnostic code No.
—
Diagnostic tool display
—
Procedure
—
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1
Connection of rectifier/regulator
coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (bent or broken
terminals and locking condition
of the pins).
Improperly connected
Con-
nect the coupler securely, or
repair/replace the wire harness.
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”
Go
to item 6 and finish the service.
Condition is “Detected”
Go to
item 2.
2
Connection of AC magneto cou-
pler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (bent or broken
terminals and locking condition
of the pins).
Improperly connected
Con-
nect the coupler securely, or
repair/replace the wire harness.
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”
Go
to item 6 and finish the service.
Condition is “Detected”
Go to
item 3.
3
Wire harness continuity.
Open or short circuit
Replace
the wire harness.
Between rectifier/regulator cou-
pler and battery terminal.
red–red
black–black
Between rectifier/regulator cou-
pler and AC magneto coupler.
white–white
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”
Go
to item 6 and finish the service.
Condition is “Detected”
Go to
item 4.
4
Defective AC magneto.
Check the AC magneto.
Refer to “CHECKING THE STA-
Start the engine and let it idle for
approximately 5 seconds.
Check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is “Recovered”
Go
to item 6 and finish the service.
Condition is “Detected”
Go to
item 5.
5
Faulty ECU.
Replace the ECU.
Service is finished.
Summary of Contents for YZ450FX 2021
Page 6: ...EAM20162 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY ...
Page 10: ......
Page 44: ...MOTORCYCLE CARE AND STORAGE 1 32 ...
Page 61: ...TIGHTENING TORQUES 2 16 ...
Page 62: ...CABLE ROUTING DIAGRAM 2 17 EAM20152 CABLE ROUTING DIAGRAM Frame and engine left side view ...
Page 64: ...CABLE ROUTING DIAGRAM 2 19 Frame and engine right side view ...
Page 66: ...CABLE ROUTING DIAGRAM 2 21 Handlebar front view ...
Page 68: ...CABLE ROUTING DIAGRAM 2 23 Frame and engine top view ...
Page 70: ...CABLE ROUTING DIAGRAM 2 25 Frame and battery top view ...
Page 72: ...CABLE ROUTING DIAGRAM 2 27 Rear brake right side view ...
Page 74: ...CABLE ROUTING DIAGRAM 2 29 ...
Page 112: ...ELECTRICAL SYSTEM 3 36 ...
Page 148: ...REAR BRAKE 4 34 system Refer to BLEEDING THE HYDRAULIC BRAKE SYSTEM on page 3 25 ...
Page 154: ...HANDLEBAR 4 40 Throttle grip free play 3 0 6 0 mm 0 12 0 24 in ...
Page 189: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Connecting rod 2 Oil nozzle 3 Crankshaft ...
Page 191: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 5 1 Oil filter element 2 Oil pump 3 Oil strainer ...
Page 270: ...WATER PUMP 6 9 ...
Page 280: ...THROTTLE BODY 7 9 ...
Page 283: ......
Page 284: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM ...
Page 288: ...ELECTRIC STARTING SYSTEM 8 5 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM ...
Page 292: ...CHARGING SYSTEM 8 9 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM ...
Page 295: ...CHARGING SYSTEM 8 12 ...
Page 296: ...SIGNALING SYSTEM 8 13 EAM20154 SIGNALING SYSTEM EAM30348 CIRCUIT DIAGRAM ...
Page 300: ...FUEL INJECTION SYSTEM 8 17 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM ...
Page 325: ...FUEL INJECTION SYSTEM 8 42 ...
Page 326: ...FUEL PUMP SYSTEM 8 43 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM ...
Page 358: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15 ...
Page 368: ...CHASSIS 10 9 ...
Page 370: ......
Page 372: ......
Page 373: ...YZ450FXM 2021 WIRING DIAGRAM BEX 2819U 10_W D indd 1 2020 05 29 15 34 30 ...
Page 374: ...YZ450FXM 2021 WIRING DIAGRAM BEX 2819U 10_W D indd 2 2020 05 29 15 34 30 ...