Yamaha YP400T Service Manual page 306

Fault code No. 16 Symptom
Used diagnostic code No. 01 (throttle position sensor)
Order Inspection operation item and
probable cause
1 Installed condition of throttle posi-
tion sensor.
2 Defective throttle position sensor
3 When fault code No. 15 has been
detected.
Fault code No. 19 Symptom
Used diagnostic code No. 20 (sidestand switch)
Order Inspection operation item and
probable cause
1 Connected state of connector
Main wiring harness ECU coupler
(blue/yellow connector)
2 Open or short circuit in wiring har-
ness and/or sub lead.
Fault code No. 21 Symptom
Used diagnostic code No. 06 (coolant temperature sensor)
Order Inspection operation item and
probable cause
1 Installed condition of sensor
2 Connected condition of connector
Inspect the coupler for any pins
that may have pulled out.
Check the locking condition of the
coupler.
3 Open or short circuit in wiring har-
ness and/or sub lead.
4 Defective coolant temperature sen-
sor.
FUEL INJECTION SYSTEM
Stuck throttle position sensor detected.
Operation item and countermeasure
Check the installed area for looseness or pinching.
Check that it is installed in the specified position.
Refer to "THROTTLE BODY AND FUEL INJEC-
TOR".
Execute the diagnostic mode (code No. 01)
Replace if defective.
Refer to "THROTTLE BODY AND FUEL INJEC-
TOR".
Refer to "Fault code No. 15".
Open circuit in the input line of ECU (blue/yellow lead) detected.
Operation item and countermeasure
Execute the diagnostic mode (code No. 20)
Check 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.
Repair or replace if there is an open circuit.
Sidestand switch signal input line of ECU coupler
blue/yellow
Coolant temperature sensor open or short circuit is detected.
Operation item and countermeasure
Check the installed area for looseness or pinching.
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/red – green/red
Execute the diagnostic mode (code No. 06)
Replace if defective.
Refer to "COOLING SYSTEM" in chapter 8.
7 - 16
FI
Reinstatement
method
Reinstated by
starting the engine,
operating it at idle,
and then racing it.
Refer to "Fault
code No. 15".
Reinstatement
method
Reinstated by
reconnecting the
wiring and retract-
ing the sidestand.
Reinstatement
method
Reinstated by turn-
ing the main switch
ON.