Yanmar 3TNV82A Troubleshooting Manual page 174

FAILURE DIAGNOSIS
Work Description
1. Check of the relay coil resistance value (relay only):
• Remove the rack actuator relay from the harness.
• Measure the resistance between relay side terminals C and D using a circuit tester.
Measurement conditions
Tester (+) side
Terminal C
Terminal D
Terminal C
Terminal D
*As a reverse-biased diode is integrated, the above-mentioned checking method is applied, and the measured value
varies depending on a circuit tester to be used.
NG Replace the rack actuator relay.
Check the relay coil resistance with the rack actuator relay and the harness being
connected. → Go to [2. Check of the relay coil resistance value (relay + harness
OK
side):]
2. Check of the relay coil resistance value (relay + harness side):
• Install the rack actuator relay to the harness.
• Remove E-ECU from the harness.
• Measure the resistance between E-ECU connectors E07 and E33 using a circuit tester.
Measurement conditions
Tester (+) side
E07
E33
E07
E33
*As a reverse-biased diode is integrated, the above-mentioned checking method is applied, and the measured value
varies depending on a circuit tester to be used.
Check the harness for correct continuity. → Go to [3. Check of harness continuity:]
NG
Check the movement of the rack actuator relay by the diagnosis tool. → Go to [4.
OK
Movement check of the relay:]
1-172
Tester (-) side
Terminal D
Terminal C
Terminal D
Terminal C
Tester (-) side
E33
E07
E33
E07
Method and Procedure of Failure Diagnosis
Measured value
Available (*)
OK when both are normal
Infinity (*)
NG: Fault of the relay internal
Infinity (*)
circuitry
Measured value
Available (*)
OK: normal
Infinity (*)
Infinity (*) NG: Harness error
TNV DI Service Manual
Status
Status