FUEL INJECTION SYSTEM
8-35
Fault code No. 39
TIP
Disconnect the fuel pump coupler when this diagnostic tool is used.
Fault code No.
39
Item
Injector: open or short circuit detected.
Fail-safe system
Unable to start engine
Unable to drive vehicle
Diagnostic code No.
36
Actuation
Actuates injector five times at one-second intervals.
“WARNING” on the Yamaha diagnostic tool blinks five times when the
injector is actuated.
Procedure
Check that injector is actuated five times by listening for the operating
sound.
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1
Connection of injector coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion 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
Defective injector.
Check the injector.
Refer to “CHECKING THE
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
Connection of wire harness
ECU coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion 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 4.
4
Wire harness continuity.
Open or short circuit
Replace
the wire harness.
Between injector coupler and
ECU coupler.
red/black–red/black
Between injector coupler and
starter relay.
red/blue–red/blue
red/yellow–red/yellow
red–red
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 YZ 2023 Series
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 187: ...INSTALLING THE TRANSMISSION 5 74...
Page 190: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 3 1 Oil filter element 2 Oil pump...
Page 191: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 5 4 1 Intake camshaft 2 Exhaust camshaft...
Page 264: ...TRANSMISSION 5 77...
Page 274: ...WATER PUMP 6 9...
Page 284: ...THROTTLE BODY 7 9...
Page 287: ......
Page 288: ...IGNITION SYSTEM 8 1 EAM20142 IGNITION SYSTEM EAM30277 CIRCUIT DIAGRAM...
Page 292: ...ELECTRIC STARTING SYSTEM 8 5 EAM20143 ELECTRIC STARTING SYSTEM EAM30279 CIRCUIT DIAGRAM...
Page 296: ...CHARGING SYSTEM 8 9 EAM20144 CHARGING SYSTEM EAM30282 CIRCUIT DIAGRAM...
Page 299: ...CHARGING SYSTEM 8 12...
Page 300: ...SIGNALING SYSTEM 8 13 EAM20154 SIGNALING SYSTEM EAM30348 CIRCUIT DIAGRAM...
Page 304: ...FUEL INJECTION SYSTEM 8 17 EAM20145 FUEL INJECTION SYSTEM EAM30284 CIRCUIT DIAGRAM...
Page 329: ...FUEL INJECTION SYSTEM 8 42...
Page 330: ...FUEL PUMP SYSTEM 8 43 EAM20146 FUEL PUMP SYSTEM EAM30287 CIRCUIT DIAGRAM...
Page 362: ...SELF DIAGNOSTIC FUNCTION AND DIAGNOSTIC CODE TABLE 9 15...
Page 372: ...CHASSIS 10 9...
Page 374: ......
Page 376: ......
Page 377: ...YZ250FXP 2023 WIRING DIAGRAM BAJ 2819U 13_WD indd 1 2022 04 01 9 58 37...
Page 378: ...YZ250FXP 2023 WIRING DIAGRAM BAJ 2819U 13_WD indd 2 2022 04 01 9 58 37...