Yamaha YZ 2017 Series, Owner'S Service Manual

Page: 336 / 410

FUEL INJECTION SYSTEM
8-32
2 Connection of wire harness
ECU coupler.
Check the locking condition
of the coupler.
Disconnect the coupler and
check the pins (bent or bro-
ken terminals and locking
condition of the pins).
Improperly connected

Connect the coupler securely
or repair/replace the wire har-
ness.
Crank the engine.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 3.
3 Wire harness continuity. Open or short circuit

Re-
place the wire harness.
Between the crankshaft posi-
tion sensor coupler and ECU
coupler.
black/blue–black/blue
gray–gray
Crank the engine.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 4.
4 Installed condition of crank-
shaft position sensor.
Check for looseness or
pinching.
Check the gap between the
crankshaft position sensor
and the pickup rotor.
Improperly installed sensor

Reinstall or replace the
sensor.
Refer to “GENERATOR AND
STARTER CLUTCH” on
page 5-62.
Crank the engine.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 5.
5 Defective crankshaft position
sensor.
Check the crankshaft position
sensor.
Refer to “CHECKING THE
CRANKSHAFT POSITION
SENSOR” on page 8-70.
Crank the engine.
Fault code number is not dis-
played

Service is finished.
Fault code number is dis-
played

Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 12
Item
Crankshaft position sensor: no normal signals are received
from the crankshaft position sensor.