Trouble Codes; Working Procedure; Diagnostic Trouble Codes - Yanmar BY Series Service Manual

TROUBLESHOOTING

TROUBLE CODES

Working Procedure

Try to form a comprehensive view of the problem. Start by asking the operator the following:
• Symptoms
• Conditions in which the fault occurs
• How often the fault occurs
• If the trouble codes have been erased
Then, extract all the stored trouble codes.
Compare them and try to conclude the probable cause of the fault before taking any other measures. The
trouble codes are stored in the order they were registered.

Diagnostic Trouble Codes

Some conditions will produce an alarm but do not generate a trouble code. An example is engine overheat
(over 108°C) caused by an obstructed seawater inlet. The overheat alarm will sound and the engine torque
will be reduced to proect the engine, but no code will be set.
Conditions that set a trouble code are generally caused by a sensor or other component sending and out of
normal range signal to the ECU. An example is a disconnected intake air pressure sensor which would set
a P0237 code.
Code Fail
No
Coolant Temp
Code
No
Coolant Temp
Code
No
Charge Air Temp
Code
No Boost Pressure
Code Reading
No
Fuel Temperature
Code
No
Neutral Switch
Code
P0001 Fuel Metering Unit
P0003 Fuel Metering Unit
P0004 Fuel Metering Unit
Fuel Rail Pressure
P0087
System Deviation
13-10
Mode
Under 0°C (32°F)
Over 108°C (226°F)
Over 110°C (230°F)
4BY - over 1.9 bar (27.5 psi) (relative*) or 2.9 bar
(42.0 psi) (absolute**)
6BY - over 2.3 bar (33.3 psi) (relative*) or 3.3 bar
(42.9 psi) (absolute**)
Over 90°C (194°F)
Only in case of analog throttle or in case of CAN-fault
(U0001), wrong configuration - neutral position
Not connected
Short circuit to Ground
Short circuit to B+
Fuel rail pressure out of range
Trouble Codes
Engine
Run or
Can
Condition
Start
1000 rpm yes
reduce yes
reduce yes
reduce yes
reduce yes
no no
reduce yes
no no
reduce yes
reduce or depends
shut off on fault
BY Service Manual
Check
Engine
Alarm
no
alarm
no
alarm
no
alarm
alarm
alarm
alarm
alarm