FUEL INJECTION SYSTEM
8-31
Fault code Er-4
SymptomRegistered 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—
Or-
derProbable cause of malfunc-
tion and checkMaintenance 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 greenTurn “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.
4 Yamaha diagnostic tool mal-
functionReplace 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.
5 Faulty ECU Replace the ECU.
