Water-In-Fuel Sensor; Crankshaft Speed Sensor - Yanmar BY Series Service Manual

ELECTRICAL AND ECU

Water-in-Fuel Sensor

This sensor monitors fuel for the presence of water
and sends the signal to the helm display. If water is
present, the resistance between the probes drops
below the threshold of 47 k-ohms and results in a
warning at the helm. It is mounted on the bottom of
the fuel filter / water separator.
The sensor output is not used by the ECU.
Results of Failed Sensor
Failure of the sensor results in:
• Loss of water-in-fuel monitoring
If this sensor is defective, no P-codes will be
generated.
Test Values
• No test values are available for this device
Figure 12-13
1 – Pin A - Black wire
2 – Pin B - Red wire
3 – Pin C - Yellow wire
12-18

Crankshaft Speed Sensor

This sensor measures the speed of the crankshaft.
This value is compared with the camshaft speed by
the ECU. It is mounted on the rear crankshaft seal
housing at the rear of the engine. The ECU
supplies 5V and ground.
The sensor signal is used by the ECU for:
• The calculation of the actual rotations of the
engine
• The check of the starting conditions
• The calculation of the injection rate at the starting
procedure
• The control of the injection start
• The calculation of the limitation of the injection
rate
• The calculation if an external regulation of the
injection rate is necessary
1
2
• The control of the glow plugs
3
• The control of the injection rate
0004170 • The control of the rail pressure
• The control at idle speed
Results of Failed Sensor
Failure of the sensor results in:
• Inability to start the engine. Engine can not run
without this sensor.
If this sensor is defective, the following P-codes
may be generated:
• P0344 - disagreement between camshaft speed
sensor and crankshaft speed sensor
• P2617 - no connection / short circuit
Component Tests
BY Service Manual