2014 YAMAHA YZ450F turn signal

FUEL INJECTION SYSTEM
8-28
Fault code50
SymptomECU: faulty ECU memory
Fail-safe systemUnable to start engine
Unable to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
Or-
der
Probable cause of malfunc-
tion and checkMaintenance jobReinstatement method
1Faulty ECUReplace the ECU.Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Check that the fault code
number is not displayed.
Fault codeWaiting for connection
SymptomNo communication signal is received from the ECU.
Fail-safe systemAble to start engine (Unable when ECU is malfunctioning)
Able to drive vehicle (Unable when ECU is malfunctioning)
Diagnostic code No.—
Diagnostic tool display—
Procedure—
Or-
der
Probable cause of malfunc-
tion and checkMaintenance jobReinstatement method
1Connection of Yamaha diag-
nostic tool coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected 
Connect the coupler secure
-
ly, or repair/replace the wire
harness.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
2Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected 
Connect the coupler secure
-
ly, or repair/replace the wire
harness.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
3Wire harness continuity.Open or short circuit  Re-
place the wire harness.
light green–light green
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.

FUEL INJECTION SYSTEM
8-29
4Yamaha diagnostic tool mal-
function
Replace the Yamaha diag-
nostic tool.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
5Faulty ECUReplace the ECU.
Fault codeEr-2
SymptomSignals from the ECU cannot be received within the specified
period of time.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
Or-
der
Probable cause of malfunc-
tion and checkMaintenance jobReinstatement method
1Connection of Yamaha diag-
nostic tool coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected 
Connect the coupler secure
-
ly, or repair/replace the wire
harness.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
2Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition of the pins).
Improperly connected 
Connect the coupler secure
-
ly, or repair/replace the wire
harness.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
3Wire harness continuity.Open or short circuit  Re-
place the wire harness.
light green–light green
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
4Yamaha diagnostic tool mal-
function
Replace the Yamaha diag-
nostic tool.
Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
5Faulty ECUReplace the ECU.
Fault code Waiting for connection
Symptom No communication signal is received from the ECU.

LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
9-4
EAS1SL1363
LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE ACTIONS
LIST OF DIAGNOSTIC CODES
COMMUNICATION ERROR WITH YAMAHA DIAGNOSTIC TOOL
Fault
codeITEMPage
12Crankshaft position sensor: no normal signals are received from the
crankshaft position sensor.8-14
13Intake air pressure sensor: open or short circuit detected.8-15
14Intake air pressure sensor: hose system malfunction (clogged or de-
tached hose)8-16
15Throttle position sensor: open or short circuit detected.8-17
16Throttle position sensor: stuck throttle position sensor is detected.8-19
21Coolant temperature sensor: open or short circuit detected.8-20
22Intake air temperature sensor: open or short circuit detected.8-21
30The vehicle has overturned.8-22
33Ignition coil: open or short circuit detected in the primary lead of the
ignition coil.8-23
39Injector: open or short circuit detected.8-25
41ECU: built-in lean angle sensor malfunction8-25
44EEPROM fault code No.: an error is detected while reading or writing
on EEPROM.8-26
46Vehicle system power supply: normal voltage is not supplied to the
ECU.8-27
50ECU: faulty ECU memory8-28
Fault
codeITEMPage
Waiting
for con
-
nection
No communication signal is received from the ECU.
8-28
Er-2Signals from the ECU cannot be received within the specified period
of time.8-29
Er-3Data from the ECU cannot be received correctly.8-30
Er-4Registered data cannot be received from the Yamaha diagnostic tool.8-31