Yamaha 2007 XP500 Service Manual page 365

Fault code No. 21
Diagnostic code No.
Order Item/components and probable cause
1 Installed condition of coolant temperature
sensor
2 Connected state of connector
Coolant temperature sensor coupler
G
Main wire harness ECU (engine)
G
coupler
3 Open or short circuit in wire harness.
4 Defective coolant temperature sensor.
Symptom Coolant temperature sensor-open or short circuit detected.
06 Coolant temperature sensor
FUEL INJECTION SYSTEM
Check or maintenance job
Check the installed area for loose-
ness or pinching.
Check the coupler for any pins
G
that may have pulled out.
Check the locking condition of
G
the coupler.
If there is a malfunction, repair it
G
and connect it securely.
Repair or replace if there is an
G
open or short circuit.
Between sensor coupler and
G
ECU coupler
(Black/Blue–Black/Blue)
(Green/Red–Green/Red)
Execute the diagnostic monitor-
G
ing mode. (Code No.06)
Replace if defective.
G
Refer to "CHECKING THE COOL-
ANT TEMPERATURE SENSOR"
on page 8-118.
8-50
Reinstatement
method
Turning the main
switch ON.