FUEL INJECTION SYSTEM
8-48
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No.
Er-4
Item
Registered data cannot be received from the Yamaha diagnos-
tic tool.
Fail-safe system
Able to start engine
Able to drive vehicle
Diagnostic code No.
—
Diagnostic tool display
—
Procedure
—
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service
completion
1
Connection of Yamaha diag-
nostic tool coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).
Improperly connected
Connect the coupler securely
or repair/replace the wire har-
ness.
Push the start switch.
Fault code number is not dis-
played
Service is finished.
Fault code number is dis-
played
Go to item 2.
2
Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).
Improperly connected
Connect the coupler securely
or repair/replace the wire har-
ness.
Push the start switch.
Fault code number is not dis-
played
Service is finished.
Fault code number is dis-
played
Go to item 3.
3
Wire harness continuity.
Open or short circuit
Re-
place the wire harness.
light green–light green
Push the start switch.
Fault code number is not dis-
played
Service is finished.
Fault code number is dis-
played
Go to item 4.
4
Yamaha diagnostic tool mal-
function.
Replace the Yamaha diag-
nostic tool.
Push the start switch.
Fault code number is not dis-
played
Service is finished.
Fault code number is dis-
played
Go to item 5.
5
Malfunction in ECU.
Replace the ECU.
Summary of Contents for YZ 2018 Series
Page 6: ...EASB916006 YAMAHA MOTOR CORPORATION U S A YZ MOTORCYCLE LIMITED WARRANTY...
Page 10: ......
Page 40: ...MOTORCYCLE CARE AND STORAGE 1 28...
Page 64: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 23...
Page 66: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 25...
Page 68: ...LUBRICATION SYSTEM CHART AND DIAGRAMS 2 27...
Page 70: ...CABLE ROUTING DIAGRAM 2 29 EASB29B065 CABLE ROUTING DIAGRAM...
Page 72: ...CABLE ROUTING DIAGRAM 2 31...
Page 74: ...CABLE ROUTING DIAGRAM 2 33...
Page 76: ...CABLE ROUTING DIAGRAM 2 35...
Page 78: ...CABLE ROUTING DIAGRAM 2 37...
Page 80: ...CABLE ROUTING DIAGRAM 2 39...
Page 82: ...CABLE ROUTING DIAGRAM 2 41...
Page 84: ...CABLE ROUTING DIAGRAM 2 43...
Page 255: ...OIL PUMP AND BALANCER GEAR 5 58 a 2 10 b 2 9 1 b 5 3 a 4 10 5 9 3 E c d 6 7 8 8 b 6...
Page 276: ...TRANSMISSION 5 79...
Page 290: ...FUEL TANK 7 5 A Left B Right 1 1 A 0 mm 0 in B 1 1 15 mm 0 59 in...
Page 296: ...THROTTLE BODY 7 11...
Page 299: ......
Page 313: ...CHARGING SYSTEM 8 14...
Page 321: ...COOLING SYSTEM For JPN 8 22...
Page 351: ...FUEL PUMP SYSTEM 8 52 EASB29B345...
Page 352: ...ELECTRICAL COMPONENTS 8 53 ELECTRICAL COMPONENTS EASB29B346 9 10 11 1 3 2 4 5 6 7 8...
Page 354: ...ELECTRICAL COMPONENTS 8 55 11 10 9 2 3 1 6 7 8 4 5...
Page 356: ...ELECTRICAL COMPONENTS 8 57 EASB29B347 CHECKING THE SWITCHES 4 1 3 2 B B Sb B B B B B B B B...
Page 372: ...ELECTRICAL COMPONENTS 8 73 c Measure the fuel injector resistance...