FI
6-22
FUEL INJECTION SYSTEM
Fault code No.
31
Symptom
The amount of air-fuel ratio feedback compesation is
maintained continously in the vicinity of the upper limit
Diagnostic code No.
—
—
Order
Item / components and
probable cause
Check or maintenance job
Reinstatement
method
1
Installed state of O
2
sensor
Check for looseness or pinching.
2
Connections
•
O
2
sensor coupler
•
Main wire harness ECU
coupler
•
Check the coupler for any pins
that may b pulled out.
•
Check the locking condition of
the coupler .
•
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 na
open or short circuit.
•
Between O
2
sensor coupler and
ECU coupler.
Gray / Red - Blue
Red / Blue – Black.
4
Check fuel pressure.
Refer to “THROTTLE BODY”.
5
Defective O
2
sensor.
(unable to output a rich signal)
Replace if defective.
Reinstated by
starting the
engine operating it at
idle 15 minutes and
running at 80 km/h
until the warning light
turns off.
Summary of Contents for YBR250 2007
Page 1: ...YBR250 SERVICE MANUAL 5D1 F8197 E0 2007 ...
Page 2: ......
Page 359: ...YAMAHA MOTOR DA AMAZÔNIA LTDA ...
