Yanmar 3TNV82A Troubleshooting Manual page 153

Method and Procedure of Failure Diagnosis
3. Check of harness continuity:
Remove the accelerator sensor and E-ECU from the harness.
•
Check the harness continuity using a circuit tester.
•
Terminal
Sensor signal wire E37
[Between E-ECU and sensor connector]
Sensor GND wire E28
[Between E-ECU and sensor connector]
Sensor 5V wire E38
[Between E-ECU and sensor connector]
Between E37 and other terminal/GND,
and between E38 and other
terminal/GND
Between E28 and GND/E45/E47
Between E28 and other terminals
NG
OK
4. Check of the sensor output voltage:
Connect the 2G eco-checker harness between E-ECU and machine's harness (for details, see [How to
•
use the 2G eco-checker harness] (P.1-135). And connect the all connectors (sensors, E-ECU).
Measure the voltage between sensor signal E37 and E28 using a circuit tester.
•
Voltage
E37 ≤ 0.2[V]
0.2[V] < E37 < 4.6[V]
4.6V ≤ E37
NG
OK
TNV DI Service Manual
• Check if the harness is damaged, or if the wiring is correct.
• Replace the harness.
Check the output voltage of the spare accelerator sensor or the atmospheric
pressure sensor. → Go to [4. Check of the sensor output voltage:]
• Check if the harness is damaged, or if the wiring is correct.
• Replace the harness.
Replace the E-ECU.
Continuity
Available OK: normal
Unavailable NG: harness disconnection
Available OK: normal
Unavailable NG: harness disconnection
Available OK: normal
Unavailable NG: harness disconnection
Unavailable OK: normal
Available NG: harness short-circuited with GND
Available OK: normal
Unavailable NG: harness disconnection
Unavailable OK: normal
NG: harness short-circuited with another
Available
wiring
Status
• Replace the harness.
NG
• Replace the sensor.
OK
Replace the E-ECU.
(normal range)
• Replace the harness.
NG
• Replace the sensor.
FAILURE DIAGNOSIS
Status
Action
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