FAILURE DIAGNOSIS
TNV DI Service Manual
1-201
Method and Procedure of Failure Diagnosis
Work Description
1. Check of the relay coil resistance value (relay only):
• Remove the E-ECU main relay from the harness.
• Check the continuity between relay side terminals A and B using a circuit tester.
2. Check of the relay coil resistance value (relay only):
• Remove the E-ECU main relay from the harness.
• Measure the resistance between relay side terminals C and D using a circuit tester.
*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.
3. Check of relay coil resistance value (relay + harness side):
• Install the E-ECU main relay to the harness.
• Remove E-ECU from the harness.
• Measure the resistance between battery cable (+) line and harness side E-ECU connector E34.
*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 E-ECU main relay.
OK
Check the resistance of the E-ECU main relay coil.
→
Go to [2. Check of the relay
coil resistance value (relay only):]
Measurement conditions
Measured value
Status
Tester (+) side
Tester (-) side
Terminal C
Terminal D
Available (*)
OK when both are normal
Terminal D
Terminal C
Infinity (*)
Terminal C
Terminal D
Infinity (*)
NG: Fault of the relay internal
circuitry
Terminal D
Terminal C
NG
Replace the E-ECU main relay.
OK
Check the relay coil resistance with the E-ECU main relay and the harness being
connected.
→
Go to [3. Check of relay coil resistance value (relay + harness side):]
Measurement conditions
Measured value
Status
Tester (+) side
Tester (-) side
Battery (+) line
E34
Available (*)
OK: normal
E34
Battery (+) line
Infinity (*)
Battery (+) line
E34
Infinity (*)
NG: Harness error
E34
Battery (+) line
NG
Replace the harness.
OK
Check the harness for correct continuity.
→
Go to [4. Check of harness continuity:]
TNV_DI_SM_A4-Troubleshooting.book 201 ページ 2007年11月15日 木曜日 午後5時27分