Engine Unit Troubleshooting (Diagnostic Code Not Detected) - Yamaha Waverunner VXS VX1800 Service Manual

Engine unit troubleshooting (diagnostic code not detected)

Troubleshooting when diagnostic codes are not available consists of the following 3 items.
Symptom 1: Specific trouble conditions
Symptom 2: Trouble conditions of an area or individual part
Cause: The contents considered to be the trouble factors for symptom 2
—: Not applicable
Symptom 1: Engine does not crank.
Symptom 2
Starter motor does
not operate
Starter motor oper-
ates, but the engine
does not crank
Symptom 1: Engine will not start (engine cranks).
Symptom 2
Throttle valve does
not move properly
Cause
Yamaha Security System
set to lock mode
Discharged battery
Loose connection of bat-
tery terminal
Blown fuse
Starter relay malfunction
Engine start switch mal-
function
Short, open, or loose con-
nection in starter motor cir-
cuit
Starter motor malfunction
Stuck piston or crankshaft
Stuck impeller
Idle gear or starter clutch
malfunction
Cause
Throttle lever squeezed
APS malfunction
TPS malfunction
Throttle valve malfunction
Checking step
Check that the Yamaha Security
System is set to the unlock mode.
Check the battery voltage and spe-
cific gravity.
Check the battery lead and terminal
for proper connection.
Check the fuse for continuity.
Check the starter relay.
Check the engine start switch. [han-
dlebar switch (left)].
Measure the starter relay input volt-
age.
Check the wire harness.
Disassemble and check the starter
motor.
Disassemble and check the engine
unit.
Disassemble and check the jet
pump unit.
Check the idle gear, starter clutch,
or crankshaft Woodruff key.
Checking step
Check that the throttle lever is in the
fully closed position.
Measure the APS 1 and 2 output
voltage.
Check the throttle valve opening.
Check the ETV.
9-15
Engine unit troubleshooting
See
page
7-37
3-6
3-6
7-3
7-31
7-32
7-31
7-32
A-2
7-34
5-73
6-10
5-55
5-60
See
page
—
7-20
7-18
4-7