Yamaha Fz1n Service Manual

FUEL INJECTION SYSTEM
8-67
B-1Installed state of neutral switch.  Check for looseness or pinch-
ing.Starting the 
engine, and 
activating the 
speed sensor 
by operating the 
vehicle at 20 to 
30 km/h.
B-2 Connections
 Neutral switch coupler
 Main wire harness ECU coupler
 Check the couplers for any pins 
that may be pulled out.
 Check the locking condition of  the couplers.
 If there is a malfunction, repair it  and connect the coupler 
securely.
B-3 Open circuit in neutral switch lead.  Repair...

FUEL INJECTION SYSTEM
8-68
Fault code No. 43 SymptomPower supply to the injectors and fuel pump is not nor-
mal.
Diagnostic code No. 09 Fuel system voltage (battery voltage)
Order Item/components and probable 
cause Check or maintenance job Reinstatement 
method
1 Connections
 Relay unit coupler (fuel pump relay)
 Main wire harness ECU coupler
 Check the couplers for any pins 
that may be pulled out.
 Check the locking condition of  the couplers.
 If there is a malfunction, repair it  and connect...

FUEL INJECTION SYSTEM
8-69
Fault code No. 44 SymptomAn error is detected while reading or writing on EEPROM 
(CO adjustment value).
Diagnostic code No. 60 EEPROM fault cylinder No.
Orde r Item/components and probable 
cause Check or maintenance job Reinstatement 
method
1 Malfunction in ECU  Set the faulty cylinder’s exhaust 
gas volume.
1 Execute the diagnostic mode (Code No. 60) to check the 
faulty cylinder number. (If mul-
tiple cylinders are defective, 
the numbers of the faulty cyl-
inders are...

FUEL INJECTION SYSTEM
8-70
Fault code No. 46 SymptomPower supply to the fuel injection system relay is not nor-
mal.
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 be pulled out.
 Check the locking condition of  the coupler.
 If there is a malfunction, repair it  and connect the coupler 
securely. Starting the 
engine and 
operating it at 
idle.
2...

FUEL INJECTION SYSTEM
8-71
Fault code No. 47 SymptomSub-throttle position sensor:open or short circuit 
detected.
Diagnostic monitor- ing code No. 56 Sub-throttle servo motor
Order Item/components and probable 
cause Check or maintenance job Reinstatement 
method
1 Installed state of sub-throttle position 
sensor.
 Check for looseness or pinch-
ing.
 Check that the sensor is 
installed in the specified posi-
tion. Turning the 
main switch to  
“ON”.
2 Connections
 Sub-throttle position sensor...

FUEL INJECTION SYSTEM
8-72
Fault code No. 48 Symptom Sub-throttle servo motor:stuck.
Diagnostic code No. 56 Sub-throttle servo motor
Order Item/components and probable 
cause Check or maintenance job
Reinstatement 
method
1 Connections
 Sub-throttle servo motor coupler
 Main wire harness ECU coupler
 Check the couplers for any pins 
that may be pulled out.
 Check the locking condition of  the couplers.
 If there is a malfunction, repair it 
and connect the coupler 
securely. Turning the 
main...

FUEL INJECTION SYSTEM
8-73
Fault code No. Er-1 Symptom No signals are received from the ECU.
Diagnostic code No. — —
Order Item/components and probable 
cause Check or maintenance job
Reinstatement 
method
1 Connections
 Main wire harness ECU coupler
 Main wire harness meter assembly 
coupler
 Sub-wire harness coupler  Check the couplers for any pins 
that may be pulled out.
 Check the locking condition of  the couplers.
 If there is a malfunction, repair it 
and connect the coupler 
securely....

FUEL INJECTION SYSTEM
8-74
Fault code No. Er-3 Symptom Data from the ECU cannot be received correctly.
Diagnostic code No. — —
Order Item/components and probable 
cause Check or maintenance job
Reinstatement 
method
1 Connections
 Main wire harness ECU coupler
 Main wire harness meter assembly 
coupler
 Sub-wire harness coupler  Check the couplers for any pins 
that may be pulled out.
 Check the locking condition of  the couplers.
 If there is a malfunction, repair it 
and connect the coupler...

FUEL PUMP SYSTEM
8-75
EAS27550
FUEL PUMP SYSTEM
EAS27560
CIRCUIT DIAGRAM 

FUEL PUMP SYSTEM
8-76
1. Main switch
6. Fuse (main)
7. Battery
8. Fuse (fuel injection)
13.Fuel pump relay
16.Fuel pump
23.ECU
46.Multi function meter
56.Engine stop switch
78.Fuse (ignition)