Yamaha YXR70FX, Service Manual

Page: 286 / 497

6 - 16
FI
FUEL INJECTION SYSTEM
Fault code No. 16 Symptom Stuck throttle position sensor detected.
Diagnostic code No. d01 Throttle position sensor
Order Item/components and probable
cause
Check or maintenance job Reinstatement
method
1 Installed condition of throttle posi-
tion sensor. • Check the installed area for
looseness or pinching.
• Check that the throttle position
sensor is installed in the speci-
fied position.
Refer to “CHECKING AND
ADJUSTING THE THROTTLE
POSITION SENSOR”.
Reinstated by
starting the
engine, operat-
ing it at idle, and
then racing it.
2 Defective throttle position sensor. • Execute the diagnostic monitor-
ing mode.
(Code No.d01)
• Replace if defective.
Refer to “CHECKING AND
ADJUSTING THE THROTTLE
POSITION SENSOR”.
Fault code No. 21 Symptom Coolant temperature sensor: open or short circuit
detected.
Diagnostic code No. d06 Coolant temperature sensor
Order Item/components and probable
cause
Check or maintenance job Reinstatement
method
1 Installed condition of coolant tem-
perature sensor. Check the installed area for loose-
ness or pinching. Turning the
main switch to
“ON”.
2 Connections
• Coolant temperature sensor cou-
pler
• Main wire harness-ECU coupler
• Check the coupler for any pins
that may have 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 har-
ness. • Repair or replace if there is an
open or short circuit.
• Between coolant temperature
sensor coupler and ECU coupler.
(black/blue–black/blue)
(green/yellow–green/yellow)
4 Defective coolant temperature
sensor. • Execute the diagnostic mode.
(Code No.d06)
• Replace if defective.
Refer to “SIGNALING SYSTEM”
in chapter 9.