Yamaha YP125R, Service Manual

Page: 446 / 498

FUEL INJECTION SYSTEM
8-49
Fault code No. 46
Item Power supply to the fuel injection system is not normal.
Fail-safe system
Able to start engine
Able to drive vehicle
Diagnostic code No. —
FI diagnostic tool display —
Checking method —
Probable cause of malfunction Check or maintenance job
1 Connections
• Wire harness ECU coupler • Check the coupler for any pins that may be
pulled out.
• Check the locking condition of the coupler.
• If there is a malfunction, repair it and connect
the coupler securely.
2 Faulty battery. • Charge or replace the battery.
Refer to “CHECKING AND CHARGING THE
BATTERY” on page 8-78.
3 Malfunction in rectifier/regulator • Replace if defective.
Refer to “CHARGING SYSTEM” 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 terminal and ECU fuse termi-
nal.
(red–red)
• Between ECU fuse terminal and ECU coupler.
(red/green–red/green)
Reinstatement method Starting the engine and operating it at idle.
Fault code No. 50
Item
Faulty ECU memory. (When this malfunction is detected in the
ECU, the fault code number might not appear on the meter.)
Fail-safe system
Unable to start engine
Unable to drive vehicle
Diagnostic code No. —
FI diagnostic tool display —
Checking method —
Probable cause of malfunction Check or maintenance job
1 Malfunction in ECU. • Replace the ECU.
TIP
Do not perform this procedure with the main
switch turned to “ON”.
Reinstatement method Turning the main switch to “ON”.