FUEL INJECTION SYSTEM
8-28
Fault code 50
Symptom ECU: faulty ECU memory
Fail-safe system Unable to start engine
Unable to drive vehicle
Diagnostic code No. —
Diagnostic tool display —
Procedure —
Or-
der
Probable cause of malfunc-
tion and check
Maintenance job Reinstatement method
1 Faulty ECU Replace the ECU. Turn “ON” the switch on the
FI diagnostic tool sub-lead.
Check that the fault code
number is not displayed.
Fault code Waiting for connection
Symptom No communication signal is received from the ECU.
Fail-safe system Able 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 check
Maintenance job Reinstatement method
1 Connection 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.
2 Connection 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.
3 Wire 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.