Yamaha 2009 XP500Y TMAX Service Manual page 343

Fault code No. 21
Diagnostic code No.
Order Item/components and probable
cause
1 Installed condition of coolant tempera-
ture sensor.
2 Connections
• Coolant temperature sensor coupler
• Wire harness ECU (engine control
unit) coupler
3 Open or short circuit in wire harness.
4 Defective coolant temperature sensor. • Execute the diagnostic mode.
Symptom Coolant temperature sensor: open or short circuit detect-
ed.
06 Coolant temperature sensor
Check or maintenance job
Check for looseness or pinching. Turning the
• Check the coupler for any pins
• Check the locking condition of
• If there is a malfunction, repair it
• Repair or replace if there is an
• Between coolant temperature
• Replace if defective.
8-46
FUEL INJECTION SYSTEM
that may have pulled out.
the coupler.
and connect the coupler se-
curely.
open or short circuit.
sensor coupler and ECU (en-
gine control unit) coupler.
(black/blue–black/blue)
(green/red–green/red)
(Code No. 06)
Refer to "CHECKING THE
COOLANT TEMPERATURE
SENSOR" on page 8-76.
Reinstatement
method
main switch to
"ON".