ELECTRICAL AND ECU
Component Tests
12-14
BY Service Manual
© 2009 Yanmar Marine International
Oil Pressure Sensor
This sensor measures the engine oil pressure and
sends the signal to the helm gauge. It is a pressure
sensitive variable resistor. It is mounted in the front
heat exchanger bracket and is connected to the
engine block via a pressure line.
The sensor output is not used by the ECU.
Results of Failed Sensor
Failure of the sensor results in loss of engine oil
pressure monitoring.
If this sensor is defective, no P-codes will be
generated.
Test Values
• Resistance at 0 bar (0 psi): 10 +3 to -5 ohm
• Resistance at 2 bar (29 psi): 52 ±4 ohm
• Resistance at 4 bar (58 psi): 88 ±4 ohm
• Resistance at 6 bar (87 psi): 124 ±5 ohm
Figure 12-9
Figure 12-9
1 – Engine Harness
2 – Engine Harness
Note: Polarity of wire connections is not
important. Either wire can be connected
to either terminal.
Fuel Injector
The fuel injectors are continuously supplied with
high-pressure fuel and are electronically triggered
by the ECU. The ECU controls the frequency,
duration and timing of injection.
Results of Failed Injector
If an injector-related failure occurs, the following
P-codes may be generated:
• P2049 - Short circuit on high side to ground or B+
• 4BY2 - engine will stop
• 6BY2 - engine may continue to run
• P2052 - Short circuit on high side to ground or B+
• Engine may continue to run
• P0261, P0264, P0267, P0270, P0273, P0276 -
short circuit to B+
• P0201, P0202, P0203, P0204, P0205, P0206, -
no connection / short to ground
Note: A minimum of two injectors must function
for the 4BY2 to run. A minimum of three
injectors must function for the 6BY2 to
run.
Test Values
Resistance at 20°C (68°F): 0.4 ohm
Figure 12-10
Figure 12-10
1 – Pin 1 - Low Side
2 – Pin 2 - High Side
0004171
(2)
(1)
000416
9
1 2