Yanmar 3TNV82A Troubleshooting Manual page 152

FAILURE DIAGNOSIS
Work Description
1. Check of the sensor resistance value (sensor only):
• Between sensor terminal A and C of the spare accelerator sensor or the atmospheric pressure sensor
(total resistance value)
Remove the harness from the spare accelerator sensor or the atmospheric pressure sensor.
•
Measure the resistance between sensor terminals A and C (total resistance value) using a circuit tester.
•
(REF) Total resistance value of Yanmar standard spare accelerator sensor or atmospheric pressure sensor
NG
OK
• Between sensor terminal A and B of the spare accelerator sensor or the atmospheric pressure sensor
Measure the resistance between sensor terminals A and B using a circuit tester.
•
Check if the resistance value between sensor terminal A and B fluctuates when the sensor opening is
•
changed.
NG
OK
2. Check of the sensor resistance value (sensor + harness):
• Between harness E38 and E28 (all the resistance value)
Connect sensor and harness, and remove E-ECU from the harness.
•
Measure the resistance between harness side E-ECU connectors E38 and E28 (all the resistance value)
•
using a circuit tester. *Refer to above-mentioned sensor resistance values.
NG
OK
• Between harness E37 and E28
Measure the resistance between E-ECU connectors E37 and E28 using a circuit tester.
•
Check if the resistance value between E-ECU connector E37 and E28 fluctuates when the sensor
•
opening is changed.
NG
OK
1-150
Terminal
Sensors A - C
Replace the spare accelerator sensor or the atmospheric pressure sensor.
Check the resistance value between terminal A and B of the spare accelerator
sensor or the atmospheric pressure sensor. → Go to [• Between sensor terminal A
and B of the spare accelerator sensor or the atmospheric pressure sensor]
Replace the spare accelerator sensor or the atmospheric pressure sensor.
Check the sensor resistance with the sensor and the harness being connected. →
Go to [2. Check of the sensor resistance value (sensor + harness):]
Check the harness for correct continuity. → Go to [3. Check of harness continuity:]
Check the resistance value between the harness E37 and E28. → Go to [• Between
harness E37 and E28]
Check the harness for correct continuity. → Go to [3. Check of harness continuity:]
Check the sensor resistance with the sensor and the harness being connected. →
Go to [2. Check of the sensor resistance value (sensor + harness):]
Method and Procedure of Failure Diagnosis
Specification
5 ± 1.5kΩ
TNV DI Service Manual