Yamaha V Star 950 Service Manual page 338

Fault code No.
Symptom
Fail-safe action
Diagnostic monitor-
ing code No.
Meter display
Checking method
Order
1
2
3
4
37
Engine speed is high when the engine is idling
Engine startup: Possible (stuck fully closed unable)
Riding: Possible
54
—
—
Item/components and
probable cause
Throttle valve does not
fully close.
ISC valve installation
status
ISC valve malfunction
ECU malfunction
7-53
FUEL INJECTION SYSTEM
Check or mainte-
nance job
Check the throttle bod-
ies.
Refer to "THROTTLE
BODIES" on page 6-6.
Check the throttle
cables.
Refer to "ADJUSTING
THE THROTTLE
CABLE FREE PLAY"
on page 3-27.
Check that the ISC unit
coupler is not discon-
nected.
The ISC valve is stuck
fully open if it does not
operate when the main
switch is turned to
"OFF".
(Touch the ISC unit
with your hand and
check if it is vibrating to
confirm if the ISC valve
is operating.)
Diagnostic mode (Code
No. 54).
Replace the ECU.
Sensor inspection
procedure
ISC valve returns to its
original position by
turning the main switch
to "ON" and back
"OFF".
Reinstated if the
engine idling speed is
within specification
after starting the
engine