Yamaha RST90GTY, Service Manual, Page: 140 / 299

62
FI
FUEL INJECTION SYSTEM
Fault code No. 25 Symptom Intake air pressure sensor 2 (cylinder #1): open or short circuit detected.
Diagnostic code No. d:04 (intake air pressure sensor 2 (cylinder #1))
Order Item/components and probable cause Check or maintenance job Reinstatement
method
1 Connections
• Intake air pressure sensor 2 (cylinder #1)
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. Setting the
engine stop
switch to “RUN”
and turning the
main switch on.
2 Open or short circuit in wire harness. Repair or replace if there is an open or short cir-
cuit.
Between the intake air pressure sensor 2 (cylin-
der #1) coupler and ECU coupler.
Black/Blue – Black/Blue
Pink/Black – Pink/Black
Blue – Blue
3 Defective intake air pressure sensor 2
(cylinder #1). Execute the diagnostic mode (code No. d:04).
Replace if defective.
1. Connect the pocket tester (DC 20 V) to the
intake air pressure sensor 2 (cylinder #1) cou-
pler terminals as shown.
2. Turn the main switch on.
3. Measure the intake air pressure sensor 2 (cyl-
inder #1) output voltage.
4. Is the intake air pressure sensor 2 (cylinder
#1) OK?
Positive tester probe
→
Pink/Black
1
Negative tester probe
→
Black/Blue
2
L P/B B/L
2 1
Intake air pressure sensor 2 (cylin-
der #1) output voltage:
3.75 ~ 4.25 V