Yamaha YZF-R125, Service Manual

Page: 322 / 356

FUEL INJECTION SYSTEM
8-51
Fault code No. 46 Symptom Power supply to the fuel injection system is not normal.
Diagnostic code No. — —
Order Item/components and probable
cause
Check or maintenance job Reinstatement
method
1 Connections
• Main wire harness ECU coupler • Check the coupler for any pins
that may have pulled out.
• Check the locking condition of
the coupler.
• If there is a malfunction, repair it
and connect the coupler se-
curely.
Starting the en-
gine and oper-
ating it at idle.
2 Faulty battery. • Replace or charge the battery.
Refer to “CHECKING AND
CHARGING THE BATTERY” on
page 8-64.
3 Malfunction in rectifier/regulator • Replace if defective.
Refer to “CHARGING SYS-
TEM” on page 8-11.
4 Open or short circuit in wire harness. Repair or replace if there is an
open or short circuit.
• Between battery and main
switch coupler
(red–red)
• Between main switch coupler
and fuse box coupler.
(brown/blue–brown/blue)
• Between fuse box coupler and
ECU coupler.
(red/black–red/black)
Fault code No. 50 Symptom Faulty ECU memory. (When this malfunction is detected in
the ECU, the fault code number might not appear on the
LCD of the FI diagnostic tool.)
Diagnostic code No. — —
Order Item/components and probable
cause
Check or maintenance job Reinstatement
method
1 Malfunction in ECU. Replace the ECU.
NOTE:
Do not perform this procedure
with the main switch set to “ON”.
Setting the
main switch to
“ON”.
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