Yamaha FZ8NA Service Manual page 496

Fault code No.
Item
Fail-safe system
Diagnostic code No.
Actuation
Procedure
Item/components and
probable cause
5 Continuity of wire harness
6 ECU malfunction
TIP
If fault codes 47 and 48 are indicated simultaneously, take the actions specified for fault code 47
first.
Fault code No.
Item
Fail-safe system
Diagnostic code No.
Meter display
Procedure
Item/components and
probable cause
1 ECU malfunction
48
Sub-throttle servo motor: stuck sub-throttle servo motor detected.
signal from sub-throttle position sensor will not change. (sub-throt-
tle servo motor will not start.)
Able to start engine
Able to drive vehicle
d:56
Sub-throttle valve will close and stops at standard position after
fully opened.
This operation takes about 3 seconds and engine trouble warning
light will be turning on during operation.
Check the operating sound of the sub-throttle servo motor.
Check or maintenance job
Open or short circuit →
Replace the wire harness
Yellow/red–Yellow/red
Yellow/white–Yellow/white
Gray/black–Gray/black
Gray/white–Gray/white
Replace the ECU.
50
Faulty ECU memory. (When this malfunction is detected in the ECU,
the fault code number might not appear on the meter.)
Unable to start engine
Unable to drive vehicle
—
—
—
Check or maintenance job
Replace the ECU.
FUEL INJECTION SYSTEM
8-101
Sensor inspection proce-
dure
Place the main switch to the
ON position, and check the
fault code indication.
No fault code indicated. →
Recovered.
Fault code indicated. →
Check the next step.
Sensor inspection proce-
dure
Place the main switch to the
ON position.
Then, check that no fault
code indicated.