Yamaha YP400T Service Manual page 305

Fault code No. 14 Symptom
Used diagnostic code No. 03 (intake air pressure sensor)
Order Inspection operation item and
probable cause
1 Intake air pressure sensor hose
detached, clogged, kinked, or
pinched.
Intake air pressure sensor mal-
function at intermediate electrical
potential.
2 Connected state of connector
Intake air pressure sensor coupler
Main wiring harness ECU coupler
3 Defective intake air pressure sen-
sor.
Fault code No. 15 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 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 Throttle position sensor lead wire
open circuit output voltage check.
5 Defective throttle position sensor.
FUEL INJECTION SYSTEM
Intake air pressure sensor - hose system malfunction (clogged or detached
hose).
Operation item and countermeasure
Repair or replace the sensor hose.
Inspect and repair the connection.
Check the coupler for any pins that may have pulled
out.
Check that the coupler is connected securely.
If there is a malfunction, repair it and connect it
securely.
Execute the diagnostic mode (code No. 03)
Replace if defective.
Refer to "Fault code No. 13".
Throttle position sensor - open or short circuit 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".
If there is a malfunction, repair it and connect it
securely.
Throttle position 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
yellow – yellow, yellow/blue – yellow/blue
blue – blue
Check for open circuit and replace the throttle posi-
tion sensor.
black/blue – yellow/blue
Execute the diagnostic mode (code No. 01)
Replace if defective.
Refer to "THROTTLE BODY AND FUEL INJEC-
TOR".
7 - 15
FI
Reinstatement
method
Reinstated by
starting the engine
and operating it at
idle.
Reinstatement
method
Reinstated by turn-
ing the main switch
ON.