Yamaha MT-01 Service Manual page 801

Manuals by Motomatrix / www.motomatrix.co.uk
Fault code No. 37
Diagnostic code No.
Order Item/components and probable
cause
1 ECU fuse is blown.
2 Throttle valve does not fully close.
3 ISC valve is stuck fully open due to
disconnected ISC unit hose or cou-
pler. (High engine idle speed is de-
tected with the ISC valve stuck fully
open even though signals for the valve
to close are continuously being trans-
mitted by the ECU.)
4 ISC valve is not moving correctly.
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Symptom Engine speed is high when the engine is idling.
54 ISC valve
FUEL INJECTION SYSTEM
Check or maintenance job
• Check the ECU fuse.
Refer to "CHECKING THE
FUSES" on page 7-93.
• Check the throttle body.
Refer to "THROTTLE BODIES"
on page 6-4.
• Check the throttle cables.
Refer to "ADJUSTING THE
THROTTLE CABLE FREE
PLAY" on page 3-7.
• Check that the ISC unit hose is
not disconnected.
• Check that the ISC unit coupler
is not disconnected.
• The ISC valve is stuck fully
open if it does not operate when
the main switch is turned "OFF".
(Touch the ISC unit with your
hand and check if it is vibrating
to confirm if the ISC valve is op-
erating.)
• Execute the diagnostic mode.
(Code No.54)
• After the ISC valve is fully
closed, it opens to the standby
opening position when the en-
gine is started. This operation
takes approximately 12 sec-
onds. Start the engine. If the er-
ror recurs, replace the throttle
body assembly.
7-55
Reinstatement
method
ISC valve re-
turns to its orig-
inal position by
turning the
main switch to
"ON" and back
to "OFF".
Reinstated if
the engine idle
speed is within
specification af-
ter starting the
engine.