Yamaha YZF-R1S Service Manual page 367

Fault code No. 21
Used diagnostic code No. 06 (coolant temperature sensor)
Order Inspection operation item and probable
cause
1 Connected condition of connector
Inspect the coupler for any pins that
may have pulled out.
Check the locking condition of the
coupler.
2 Open or short circuit in wiring harness
and / or sub lead.
3 Defective coolant temperature sensor.
FUEL INJECTION SYSTEM
Symptom Open or short circuit is detected from the coolant temperature sensor.
Operation item and countermeasure
If there is a malfunction, repair it and connect it
securely.
Coolant temperature sensor coupler
Main wiring harness ECU coupler
Sub-wire harness coupler
Repair or replace if there is an open or short
circuit.
Between sensor coupler and ECU coupler
Black / Blue – Black / Blue
Green / White – Green / White
Execute the diagnostic mode (Code No.06).
Replace if defective.
Refer to "COOLING SYSTEM" in chapter 8.
7-23
FI
Reinstatement
method
Reinstated by
turning the
main switch
ON.