Engine Unit Trouble Analysis; Using The Ydis For Engine Unit Trouble Analysis - Yamaha WaveRunner FX SHO Service Manual

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Engine unit trouble analysis

Engine unit trouble analysis
NOTE:
• Before troubleshooting the engine unit, make sure that fresh fuel of the specified type has been
used.
• Check that the battery is charged and that its specific gravity is within specification.
• Check the diagnostic code using the YDIS (or self-diagnosis) first, and then check the electronic
control system by following the diagnostic code chart.
• The multifunction meter cannot display more than 1 diagnostic code. Even if multiple diagnostic
codes are present, only 1 will be displayed.
• When a three-digit diagnostic code is detected, check the data logger of the "ECM record data
graph" as well.
• Using the YDIS is recommended because self-diagnosis may be insufficient for proper trouble-
shooting of the ETV system (throttle body assembly, TPS, and APS).
• If a diagnostic code is not detected, check the engine unit according to "Engine unit trouble analy-
sis (diagnostic code not detected)."
• Before using the YDIS or checking the engine unit, check the ECM circuit. To check the ECM cir-
cuit, refer to "ECM circuit" in Chapter 7.
• Check that all wiring connections are properly secured and that they are not rusty or corroded.
• Check that the engine shut-off cord (lanyard) is connect to the engine shut-off switch.
• When deleting the diagnosis record on the YDIS, be sure to check the time that the diagnostic
codes were detected.
• When checking the input voltage of a part, the coupler or connector must be disconnected. As a
result, the ECM determines that the part is disconnected and a diagnostic code is detected.
Therefore, be sure to delete the diagnosis record after checking the input voltage.

Using the YDIS for engine unit trouble analysis

NOTE:
• Use the diagnostic codes displayed by the YDIS to check each part according to the "Diagnostic
code and checking step" table.
• Delete the diagnostic codes after checking, repairing, or replacing a part, and check that the diag-
nostic codes are not detected again. If the same diagnostic codes are detected, the ECM may be
faulty.
• Check the items listed in the table, if all the items are in good condition, delete the diagnostic
code, and then check the diagnostic codes again. If the same diagnostic codes are detected
again, the ECM is faulty.
• A breakdown of the engine symptoms are described in the table below, however, multiple mal-
functions that have been duplicated cannot be limited to these items. The symptoms may change
according to the operating conditions and other conditions.
9-6
E
1
2
3
4
5
6
7
8
9