Yamaha TMAX XP530E-A 2017 Service Manual page 487

Fault code No.
Item
3 Check the electronic throttle
valve fuse.
4 Wire harness continuity.
5 Defective throttle servo motor.
6 Defective throttle bodies.
7 Malfunction in ECU.
8 Delete the fault code and check
that the engine trouble warning
light goes off.
P0638
YCC-T drive system: malfunction detected.
Abnormality  Replace the
electronic throttle valve fuse.
Open or short circuit  Replace
the wire harness.
Between throttle servo motor
coupler and ECU coupler.
yellow/red–yellow/red
yellow/red–yellow/red
Between ECU coupler and fuse
box (electronic throttle valve
fuse).
red/blue–red/blue
Check the throttle servo motor.
Replace the throttle bodies if
defective.
Refer to "CHECKING THE
THROTTLE SERVO MOTOR"
on page 8-247.
Check the throttle bodies.
Replace if defective.
Refer to "CHECKING THE
THROTTLE SERVO MOTOR"
on page 8-247.
Replace the ECU.
Refer to "REPLACING THE
ECU" on page 8-211.
Confirm that the fault code has
a condition of "Recovered"
using the Yamaha diagnostic
tool, and then delete the fault
code.
8-96
FUEL INJECTION SYSTEM
Push the ON/start switch, and
then check the condition of the
fault code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 8 and finish the service.
Condition is "Detected"  Go to
item 4.
Push the ON/start switch, and
then check the condition of the
fault code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 8 and finish the service.
Condition is "Detected"  Go to
item 5.
Push the ON/start switch, and
then check the condition of the
fault code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 8 and finish the service.
Condition is "Detected"  Go to
item 6.
Push the ON/start switch, and
then check the condition of the
fault code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 8 and finish the service.
Condition is "Detected"  Go to
item 7.
Service is finished.