Yanmar 6LY3 series Service Manual page 370

TROUBLESHOOTING
• Check the sensor signal output and the 5V sensor voltage.
A - B (pressure sensor connector)
A - C (pressure sensor connector)
Replace the pressure sensor.
Defective
Replace the ECU if the pressure sensor replacement does not make a difference.
OK Replace the ECU.
Comment: Sensor signal output range
Terminals
Wire harness connector A - B
4. Checking the 5V sensor wire harness:
• Disconnect the ECU and unplug the sensor connector.
• Check for an open / short circuit (continuity test).
Terminals
[ECU_SNS5] - C
[ECU_SNS5] - A / B /
other terminal /
ground / Battery +
Case 2: When the DTC is not active (logged status):
• ECU stores the DTC information and the YDT indicates a logged DTC. If a connector comes loose, it may
be the reason for a logged DTC.
• Clear the DTC information first, then it becomes easy to identify when the new DTC comes on.
• Check the wire harness around the pressure sensor and ECU. Check if DTC comes again.
DTC
Yes
No
13-80
Terminals
Voltage
Below 0.5V
Just below 0.5V may be
an error.
0.5V <
[ECU_P***]
V < 3.6V
above 3.6V
Continuity
Good
Defective
Defective
Good
Check if the DTC comes on.
Check the connector terminal and wire harness.
Replace the wire harness.
No action at this time
Wait and see if same DTC occurs.
© 2007 Yanmar Marine International
Troubleshooting by DTC Fault Codes
0.5V (engine stopped)
Wire harness is already checked at 1.
Failure:
1. Open circuit B- [ECU_P***]
2. Open circuit C- [ECU-SNS5]
3. Short to ground circuit B- [ECU_P***]
OK: Normal
Failure:
1. Short to battery C- [ECU_SNS5]
2. Short to battery B- [ECU_P***]
OK: Normal
Failure: Open circuit
OK: Normal
Failure: Short circuit
Contents
6LY3 Service Manual
Value
5V
Status
Status