Yamaha YZF-R1P Service Manual page 358

Fault code No. 18
Used diagnostic code 53
Inspection operation item and probable cause Operation item and countermeasure
Defective EXUP servo motor.
Open or short circuit in wire harness.
Connected condition of connector
Inspect the coupler for any pins that may
have pulled out.
Check the locking condition of the coupler.
FUEL INJECTION SYSTEM
Symptom EXUP servo motor is stuck.
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 ser-
vomotor coupler as shown.
Positive battery terminal → red 1
Negative battery lead → black 2
4. Check that the EXUP servomotor pulley
rotates several times.
CAUTION:
To prevent damaging the EXUP servomo-
tor, perform this test within a few seconds
of connecting the battery.
5. Does the EXUP servomotor pulley turn?
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
If there is a malfunction repair it and connect it
securely.
EXUP servo motor coupler
Main wire harness ECU coupler.
7 - 17
FI
Reinstatement
method
Reinstated by turn-
ing the main switch
ON.
It takes 120 sec-
onds at the maxi-
mum before the
original state
returns.
1
2