TROUBLESHOOTING
Troubleshooting by Symptom
12/05
6LY3 Service Manual
13-13
© 2007 Yanmar Marine International
The engine cannot be
controlled. Engine speed does
not increase.
Engine is overloaded.
Check around the propeller
and the boat hull.
—
CAN communication error or
main throttle error detected.
(Main throttle cannot be
activated.)
Faulty control head. (Main
throttle can be activated.)
Check the input value of the
acceleration sensor with a
YDT. If an error is detected,
correct or replace the harness.
If error is not detected and a
malfunction is found, replace
the control head.
Refer to the
YDT Manual
. If a
main throttle error is detected,
engine speed goes to idle.
Sub-throttle or wire harness
failed (in operation by
sub-throttle).
Check the input value of
acceleration sensor with a
YDT. If an error is not detected,
check the signal voltage of the
sub-throttle sensor. If failure is
found, correct or replace the
wire harness or sub-throttle
sensor.
Refer to the
YDT Manual
.
Refer to
Figure 13-1 on
page 13-14.
The engine cannot be
controlled. Engine speed is not
reduced.
Faulty control head. (Main
throttle can be activated.)
Check the input value of the
acceleration sensor with a
YDT. If an error is not detected
and a malfunction is found,
replace the control head.
Refer to the
YDT Manual
.
If a main throttle error is
detected, engine speed goes
to idle.
Sub-throttle or wire harness
failed. (In operation by
sub-throttle.)
Check the input value of the
acceleration sensor with a
YDT. If an error is not detected,
check the signal voltage of the
sub-throttle sensor. If failure is
found, correct or replace the
wire harness or sub-throttle
sensor.
Refer to the
YDT Manual
.
Refer to
Figure 13-1 on
page 13-14.
Error of rack position sensor:
Detected error (P1201).
➝
DTC:
See Troubleshooting by
DTC Fault Codes on
page 13-28
.
Fuel injection pump rack is
stuck.
Check the rack log with a YDT.
If a malfunction is found,
replace the fuel injection pump.
Refer to the
YDT Manual
.
The engine cannot be
controlled.
The gearbox connector is
disconnected.
Wire according to the manual.
See Alternator Wiring Diagram
on page 11-8
.
The gearbox cannot be
engaged or disengaged.
Faulty contact of the gearbox
connector.
Check the connector terminal.
Repair if necessary.
See Alternator Wiring Diagram
on page 11-8
.
Open circuit in the gearbox
harness.
Check the harness.
See Alternator Wiring Diagram
on page 11-8
.
Faulty electromagnetic valve
on the gearbox.
Replace the electromagnetic
valve.
Refer to the
Gearbox Manual
.
Low gearbox oil.
Check the oil level. If low, refill. Refer to the
Gearbox Manual
.
Faulty gearbox hydraulic oil
pump.
Disassemble and check.
Replace if necessary.
Refer to the
Gearbox Manual
.
Worn clutch friction discs.
Disassemble and check.
Replace if necessary.
Refer to the
Gearbox Manual
.
The engine cannot be
controlled. The shift position
cannot be changed.
Seized clutch friction discs.
Disassemble and check.
Replace if necessary.
Refer to the
Gearbox Manual
.
Trouble symptom
Causes
Corrective action
Remarks