Yamaha YZ250F(E) Owner's Service Manual page 309

Fault code
Symptom
Fail-safe system
Diagnostic code No.
Actuation
Procedure
Or- Probable cause of malfunc-
der tion and check
1 Connection of ignition coil
coupler.
Check the locking condition
of the coupler.
Disconnect the coupler, and
check the pins (for bent or
broken terminals and locking
condition 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
broken terminals and locking
condition of the pins).
3 Wire harness continuity.
4 Mounted condition of ignition
coil.
Check for looseness or
pinching.
Check the mounted condition
for correctness.
5 Defective ignition coil (test
the primary coils for continu-
ity).
33
Ignition coil: open or short circuit detected in the primary lead
of the ignition coil.
Unable to start engine
Unable to drive vehicle
30
Actuates the ignition coil five times at one-second intervals.
"WARNING" on the Yamaha diagnostic tool blinks five times when-
ever the ignition coil is actuated.
Check that a spark is generated five times.
• Connect an ignition checker.
Maintenance job
Improperly connected 
Connect the coupler secure-
ly, or repair/replace the wire
harness.
Improperly connected 
Connect the coupler secure-
ly, or repair/replace the wire
harness.
Open or short circuit  Re-
place the wire harness.
Between ignition coil coupler
and ECU coupler.
orange–orange
Improperly mounted ignition
coil  Remount or replace
the ignition coil.
Check the primary resistance
of the ignition coil.
"CHECKING THE IGNITION
COIL" on page 8-41.
8-23
FUEL INJECTION SYSTEM
Reinstatement method
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.
After starting the engine, idle
this and wait about 5 sec-
onds.
Fault code No. is not dis-
played  Repair is finished.
Fault code No. is displayed 
Go to next order.