Yamaha YZF-R1S Service Manual - page 365
7-21
FUEL INJECTION SYSTEM
FI
To prevent damaging the EXUP servomo-
tor, perform this test within a few seconds
of connecting the battery.
Positive battery terminal
! black/green
Negative battery lead
! black/red
1
2
CAUTION:
Fault code No.
18
Symptom
EXUP servo motor is stuck.
Used diagnostic code 53
Order
Inspection operation item and probable
couse
Operation item and countermeasure
Reinstatement
method
1
Connected condition of connector
Inspect the coupler for any pins that
may have pulled out.
Check the locking condition of the
coupler
If there is a malfunction repair it and
connect it securely.
EXUP servo motor coupler
Main wire harness ECU coupler.
Reinstated by
turning the
main switch
ON.
It takes 120
2
Open or short circuit in wire harness.
Repair or replace if there is an open
or short circuit.
Between motor coupler and ECU coupler.
Black / Green – Black / Green
Black / Red – Black / Red
seconds at the
maximum
before the
original state
returns.
3
Defective EXUP servo motor.
Execute the diagnostic mode (Code No.53).
Replace if defective.
1. Disconnect the EXUP cables from the EXUP
servomotor pulley.
2. Disconnect the EXUP servomotor coupler from
the wire harness.
3. Connect the battery leads to the EXUP servo-
motor coupler as shown.
4. Check that the EXUP servomotor pulley ro-
tates several times.
5. Does the EXUP servomotor pulley turn?
4
Defective EXUP valve, pulley, cable.
Replace if defective