FUEL INJECTION SYSTEM
9-31
ECU detects an abnormal signal from a sensor
If the ECU detects an abnormal signal from a sensor while the vehicle is being driven, the ECU illu-
minates the engine trouble warning light and provides the engine with alternate operating instructions 
that are appropriate for the type of malfunction.
When an abnormal signal is received from a sensor, the ECU processes the specified values that are 
programmed for each sensor in order to provide the engine with alternate operating instructions that 
enable the engine to continue operating or stop operating, depending on the conditions. 
EAS2GBB375TROUBLESHOOTING METHOD
The engine operation is not normal and the engine trouble warning light comes on.
1. Check:
• Fault code number
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a. Connect the Yamaha diagnostic tool. Refer to “YAMAHA DIAGNOSTIC TOOL” on page 9-32.
b. Check the fault code number displayed on the Yamaha diagnostic tool.
c. Identify the faulty system with the fault code number.
d. Identify the probable cause of the malfunction.
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2. Check and repair the probable cause of the malfunction.
3. Perform the reinstatement action for the fuel injection system. Refer to “Confirmation of service 
completion” in the appropriate table in “TROUBLESHOOTING DETAILS” on page 9-35.
4. After pushing the engine stop switch, push the start switch to check whether the fault code number 
is displayed.
TIP
If another fault code number is displayed, repeat steps (1) to (4) until no fault code number is dis-
played.
5. Erase the malfunction history in the diagnostic mode. Refer to “SENSOR OPERATION TABLE” 
(Diagnostic code No.62).
TIP
Turning off the meter light will not erase the malfunction history.
The engine operation is not normal, but the engine trouble warning light does not come on.
1. Check the operation of the following sensors and actuators in the diagnostic mode. Refer to 
“TROUBLESHOOTING DETAILS” on page 9-35.
If a malfunction is detected in the sensors or actuators, repair or replace all faulty parts.
If no malfunction is detected in the sensors and actuators, check and repair the inner parts of the 
engine.Fault code No. No fault code No.
Check and repair. Refer to “TROUBLESHOOT-
ING DETAILS” on page 9-35.
Monitor the operation of the sensors and actua-
tors in the diagnostic mode. Refer to “TROU-
BLESHOOTING DETAILS” on page 9-35 and 
“LIST OF SELF-DIAGNOSTIC AND FAIL-SAFE 
ACTIONS” on page 10-5.Check and repair.
01: Throttle position sensor signal (throttle angle)
30: Ignition coil
36: Injector 
ELECTRICAL COMPONENTS
9-67
EAS27990CHECKING THE BULBS AND BULB SOCK-
ETS
TIP
Do not check any of the lights that use LEDs.
Check each bulb and bulb socket for damage 
or wear, proper connections, and also for con-
tinuity between the terminals.
Damage/wear  Repair or replace the bulb, 
bulb socket or both.
Improperly connected  Properly connect.
No continuity  Repair or replace the bulb, 
bulb socket or both.
Types of bulbs
The bulbs used on this vehicle are shown in the 
illustration on the left.
• Bulbs “a” and “b” are used for the headlights 
and usually use a bulb holder that must be de-
tached before removing the bulb. The majority 
of these types of bulbs can be removed from 
their respective socket by turning them coun-
terclockwise.
• Bulbs “c” is used for turn signal and can be re-
moved from the socket by pushing and turn-
ing the bulb counterclockwise.
Checking the condition of the bulbs
The following procedure applies to all of the 
bulbs.
1. Remove:
•Bulb
EWA
WARNING
Since the headlight bulb gets extremely hot, 
keep flammable products and your hands 
away from the bulb until it has cooled down.
ECA
NOTICE
• Be sure to hold the socket firmly when re-
moving the bulb. Never pull the lead, oth-
erwise it may be pulled out of the terminal 
in the coupler.
• Avoid touching the glass part of the head-
light bulb to keep it free from oil, otherwise 
the transparency of the glass, the life of 
the bulb, and the luminous flux will be ad-
versely affected. If the headlight bulb gets 
soiled, thoroughly it with a cloth moist-
ened with alcohol or lacquer thinner.
2. Check:
• Bulb (for continuity)
(with the pocket tester)
No continuity  Replace.
TIP
Before checking for continuity, set the pocket 
tester to “0” and to the “ 1” range.
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a. Connect the positive tester probe to terminal 
“1” and the negative tester probe to terminal 
“2”, and check the continuity.
b. Connect the positive tester probe to terminal 
“1” and the negative tester probe to terminal 
“3”, and check the continuity.
c. If either of the readings indicate no continu-
ity, replace the bulb.
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Pocket tester
90890-03112
Analog pocket tester
YU-03112-C