Troubleshooting Details (Fault Code) - Yamaha YZ450FN 2022 Owner's Service Manual

EAM30286

TROUBLESHOOTING DETAILS (FAULT CODE)

This section describes the measures per fault code number displayed on the Yamaha diagnostic tool.
Check and service the items or components that are the probable cause of the malfunction following
the order given.
After the check and service of the malfunctioning part have been completed, delete the fault codes dis-
played on the Yamaha diagnostic tool according to the reinstatement method.
Fault code No.:
Fault code number displayed on the Yamaha diagnostic tool when the engine failed to work normally.
Diagnostic code No.:
Diagnostic code number to be used when the diagnostic mode is operated. Refer to "DIAGNOSTIC
CODE: SENSOR OPERATION TABLE" on page 9-12.
Parts connected to the ECU
The following parts are connected to the ECU.
When checking for a power short circuit, the couplers must be disconnected from all of the following
parts beforehand.
• Crankshaft position sensor
• Fuel injector
• Ignition coil
• Throttle position sensor
Fault code No. 12
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Diagnostic tool display
Procedure
Probable cause of malfunc-
Item
tion and check
1 Connection of crankshaft posi-
tion sensor coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion of the pins).
2 Connection of wire harness
ECU coupler.
Check the locking condition of
the coupler.
Disconnect the coupler, and
check the pins (for bent or bro-
ken terminals and locking condi-
tion of the pins).
• Intake air pressure sensor
• Coolant temperature sensor
• Intake air temperature sensor
12
Crankshaft position sensor: no normal signals are received from
the crankshaft position sensor.
Unable to start engine
Unable to drive vehicle
—
—
—
Maintenance job
Improperly connected  Con-
nect the coupler securely, or
repair/replace the wire harness.
Improperly connected  Con-
nect the coupler securely, or
repair/replace the wire harness.
8-19
FUEL INJECTION SYSTEM
Confirmation of service com-
pletion
Crank the engine, and then
check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 2.
Crank the engine, and then
check the condition of the fault
code using the malfunction
mode of the Yamaha diagnostic
tool.
Condition is "Recovered"  Go
to item 7 and finish the service.
Condition is "Detected"  Go to
item 3.