TROUBLESHOOTING
Troubleshooting by DTC Fault Codes
12/05
6LY3 Service Manual
13-79
© 2007 Yanmar Marine International
Case 1: When DTC is ACTIVE
To identify the cause (wire harness, sensor failure or connector):
1. Checking the 5V sensor output voltage:
• Unplug sensor.
• Measure the voltage between terminals A and C.
NOTICE:
[ECU_SNS5] short to ground is shown as P1230/1.
[ECU_SNS5] short to battery is shown as P1230/0.
2. Checking the wire harness for an open / short:
• Disconnect the ECU and unplug the sensor.
• Check for open / short in wire harness (continuity test).
3. Checking the sensor performance:
• Connect the ECU and plug in the sensor.
• Turn the key on and supply voltage to the ECU.
• Measure the voltage.
• Use the breakout box.
Terminals
Voltage
Status
Wire harness
connector 1 - 3
5V
OK: Normal
➝
Go to 2 “Check wire harness for an open / short.”
not 5V
Failure:
➝
Go to 4 “Check 5V sensor wire harness open / short.”
Terminals
Continuity
Status
[ECU_P***] - B
Good
OK: Normal
Defective
Failure:
Open circuit
[ECU_SNS5] - C
Good
OK: Normal
Defective
Failure:
Open circuit
[ECU_G_S] - A /
ground / 11 / 33 / 34
Good
OK: Normal
Defective
Failure:
Open circuit
[ECU_P***] - A / C /
other terminal /
ground / B
Defective
OK: Normal
Good
Failure:
Short circuit
[ECU_SNS5] - A / B /
other terminal /
ground / B
Defective
OK: Normal
Good
Failure:
Short circuit
[ECU_S_G] - B / C /
other terminal /
ground / B
Defective
OK: Normal
Good
Failure:
Short circuit
Defective
➝
Replace the wire harness.
Check the wire harness for damage or incorrect wiring.
OK
Go to 3 “Check Sensor Performance.”
