maintenance YAMAHA WR 250F 2015 Owner's Guide

FUEL INJECTION SYSTEM
9-52
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay. Fault code No. 50
ItemFaulty ECU memory. (When this malfunction is detected in the
ECU, the fault code number might not appear on the meter.)
Fail-safe systemUnable to start engine
Unable to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation of service
completion
1 Malfunction in ECU. Replace the ECU. Push the start switch.
Check that the fault code
number is not displayed.
Fault code No. waiting for connection
Item No 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—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation 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.

FUEL INJECTION SYSTEM
9-53
TIP
Before troubleshooting, disconnect the starter motor lead from the starter motor. 3 Wire harness continuity. Open or short circuit  Re-
place the wire harness.
light green–light greenPush 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.
Fault code No. Er-2
ItemSignals 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—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation 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 greenPush the start switch.
Fault code number is not dis-
played  Service is finished.
Fault code number is dis-
played  Go to item 4. Fault code No. waiting for connection
Item No communication signal is received from the ECU.

FUEL INJECTION SYSTEM
9-54
TIP
Before troubleshooting, disconnect the starter motor lead from the starter motor. 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.
Fault code No. Er-3
Item Data from the ECU cannot be received correctly.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation 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 greenPush 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. Fault code No. Er-2
ItemSignals from the ECU cannot be received within the specified
period of time.

FUEL INJECTION SYSTEM
9-55
TIP
Before troubleshooting, disconnect the starter motor lead from the starter relay.
Fault code No. Er-4
ItemRegistered data cannot be received from the Yamaha diagnos-
tic tool.
Fail-safe systemAble to start engine
Able to drive vehicle
Diagnostic code No.—
Diagnostic tool display—
Procedure—
ItemProbable cause of malfunc-
tion and checkMaintenance jobConfirmation 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 greenPush 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.