Yamaha YZ 2019 Series, Owner'S Service Manual

Page: 325 / 398

FUEL INJECTION SYSTEM
8-26
Fault code No. 13
TIP
• If fault code numbers 13 and 14 are both displayed, perform the checks and maintenance jobs for fault
code number 13 first.
• Before troubleshooting, disconnect the starter motor lead from the starter relay.
5 Defective crankshaft position
sensor.
Check the crankshaft position
sensor.
Refer to “CHECKING THE
CRANKSHAFT POSITION
SENSOR” on page 8-63.
Crank the engine.
Fault code number is not dis-
played

Service is finished.
Fault code number is displayed

Go to item 6.
6 Malfunction in ECU. Replace the ECU.
Fault code No. 13
Item Intake air pressure sensor: open or short circuit detected.
Fail-safe system
Able to start engine
Able to drive vehicle
Diagnostic code No.
03
Diagnostic tool display
Displays the intake air pressure.
Procedure
Operate the throttle while pushing the start switch. (If the display value
changes, the performance is OK.)
Item
Probable cause of malfunc-
tion and check
Maintenance job
Confirmation of service com-
pletion
1 Connection of intake air pres-
sure sensor coupler.
Check the locking condition of
the coupler.
Disconnect the coupler and
check the pins (bent or broken
terminals and locking condition
of the pins).
Improperly connected

Con-
nect the coupler securely or
repair/replace the wire harness.
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is displayed

Go to item 2.
2 Connection of wire harness
ECU coupler.
Check the locking condition of
the coupler.
Disconnect the coupler and
check the pins (bent or broken
terminals and locking condition
of the pins).
Improperly connected

Con-
nect the coupler securely or
repair/replace the wire harness.
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is displayed

Go to item 3.
3 Wire harness continuity. Open or short circuit

Replace
the wire harness.
Between intake air pressure
sensor coupler and ECU cou-
pler.
black/blue–black/blue
pink–pink
blue–blue
Push the start switch.
Fault code number is not dis-
played

Service is finished.
Fault code number is displayed

Go to item 4.
Fault code No. 12
Item
Crankshaft position sensor: no normal signals are received from
the crankshaft position sensor.