Yamaha F150B, Service Manual

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5-13
ELEC
Electrical system
Checking the electrical
component
Checking by use of YDIS
When checking the TPS, ISC, high-pressure
fuel pump, fuel injector, or each sensor, use
the YDIS.
When deleting the diagnosis record in the
YDIS, be sure to check the time that the trou-
ble codes were detected.
When checking the input voltage of a part,
the coupler or connector must be discon-
nected. As a result, the engine ECM deter-
mines that the part is disconnected and a
trouble code is detected. Therefore, be sure
to delete the diagnosis record after checking
the input voltage.
Since the main relay stays on for approxi-
mately 10 seconds after the start switch is
turned to “OFF,” the power of the engine ECM
cannot be turned off. Therefore, if the start
switch is turned to “ON” within 10 seconds
after it was turned to “OFF,” the trouble codes
cannot be deleted.
TIP:
• Before checking the electrical components,
make sure that the battery is fully charged.
• Install the proprietary YDIS software in CD-
ROM to your computer. Always use the
exclusive communication cable for connect-
ing the ECM to the computer. For a descrip-
tion of the communication cable and CD-
ROM to be used, see “YDIS” (4-1). Also, be
sure to check the CD-ROM version before
using it.
• To connect and operate the YDIS, see the
YDIS (Ver. 1.30 or later) Instruction Manual.
Measuring the peak voltage
When checking the peak voltage, do not
touch any of the connections of the digital
tester probes.
When testing the voltage between the ter-
minals of an electrical component with
the digital tester, do not allow any of the
leads to touch any metal parts. If touched,
the electrical component can be short-cir-
cuited and be damaged.
To check the electrical components or mea-
sure the peak voltage, use the special ser-
vice tools. A faulty electrical component can
be easily checked by measuring the peak
voltage. The specified engine speed when
measuring the peak voltage is affected by
many factors such as fouled spark plugs or a
weak battery. If one of these factors is
present, the peak voltage cannot be mea-
sured properly.
TIP:
• Before measuring the peak voltage, check
all wiring for proper connection and corro-
sion, and check that the battery is fully
charged.
• Use the Peak voltage adapter B with the
recommended digital circuit tester.
• Connect the positive pin of the Peak voltage
adapter B to the positive terminal of the dig-
ital tester, and the negative pin to the nega-
tive terminal.
• When measuring the peak voltage, set the
selector on the digital circuit tester to the
DC voltage mode.
Checking by use of the digital tester
The electrical technical data apply to the
measurements taken by the Yamaha recom-
mendation tester.
YDIS (CD-ROM, Ver. 1.30):
60V-WS853-04
YDIS (KIT): 60V-85300-04
Digital circuit tester: 90890-03174
Peak voltage adapter B: 90890-03172
DC V