Yamaha RST90GTZ, Service Manual

Page: 347 / 504

FI
7-20
Fault code No. 14 Symptom
Intake air pressure sensor 1 (cylinders #1, #2, and #3): hose system malfunc-
tion (clogged or detached hose).
Diagnostic code No. d:03 (intake air pressure sensor 1 (cylinders #1, #2, and #3))
Order
Item/components and probable cause Check or maintenance job Reinstate-
ment method
1
Intake air pressure sensor 1 (cylinders #1,
#2, and #3) hoses are detached, clogged,
kinked, or pinched. Repair or replace the intake air pressure sensor 1
(cylinders #1, #2, and #3) hoses. Starting the
engine and
operating it at
idle.
2
Defective intake air pressure sensor 1 (cyl-
inders #1, #2, and #3). Execute the diagnostic mode (code No. d:03).
Replace if defective.
Refer to “Fault code No. 13”.
Fault code No. 15 Symptom Throttle position sensor: open or short circuit detected.
Diagnostic code No. d:01 (throttle position sensor)
Order
Item/components and probable cause Check or maintenance job Reinstate-
ment method
1
Installed condition of throttle position sen-
sor. Check for looseness or pinching.
Check that it is installed in the specified position.
Refer to “THROTTLE BODY”. Setting the
engine stop
switch to
“RUN” and
turning the
main switch
on.
2
Connections
• Throttle position sensor coupler
• Wire harness ECU coupler Check the couplers for any pins that may have
pulled out.
Check the locking condition of the couplers.
If there is a malfunction, repair it and connect the
coupler securely.
3
Open or short circuit in wire harness. Repair or replace if there is an open or short circuit.
Between the throttle position sensor coupler and
ECU coupler.
Black/Blue – Black/Blue
Yellow – Yellow
Blue – Blue
4
Throttle position sensor lead open circuit
output voltage check. Check for open circuit and replace the throttle posi-
tion sensor.
Black/Blue – Yellow
Open circuit item Output voltage
Ground wire open circuit 5 V
Output wire open circuit 0 V
Power supply wire open
circuit 0 V
5
Defective throttle position sensor. Execute the diagnostic mode (code No. d:01).
Replace if defective.
Refer to “THROTTLE BODY”.
6 Malfunction in ECU. Replace the ECU.
FUEL INJECTION SYSTEM