FAILURE DIAGNOSIS
TNV DI Service Manual
1-159
Method and Procedure of Failure Diagnosis
3. Check of harness continuity:
• Remove the cooling water temperature sensor and E-ECU from the harness.
• Check the harness continuity using a circuit tester.
4. Output voltage check of the cooling water temperature sensor:
• 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 E16 and E28 (E35 and E28) using a circuit tester.
Terminal
Continuity
Status
Sensor signal wire E16 (E25)
[E-ECU ñ between sensor connector]
Available
OK: normal
Unavailable
NG: harness disconnection
Sensor GND wire E28
[Between E-ECU and sensor connector]
Available
OK: normal
Unavailable
NG: harness disconnection
Between E16 and other terminal/GND
(between E25 and other terminal/GND)
Unavailable
OK: normal
Available
NG: harness short-circuited with GND
E28 ñ GND/E45/E47
Available
OK: normal
Unavailable
NG: harness disconnection
Between E28 and other terminals
Unavailable
OK: normal
Available
NG: harness short-circuited with another
wiring
NG
• Check if the harness is damaged, or if the wiring is correct.
• Replace the harness.
OK
Check the output voltage of the cooling water temperature sensor.
→
Output voltage check of the cooling water temperature sensor:]
Voltage
Status
Action
E16(E25)
≤
0.2[V]
NG
• Replace the harness.
• Replace the cooling water temperature sensor.
0.2[V] < E16(E25) < 4.8V
OK
(Normal range)
ReplaceE-ECU.
4.8V
≤
E16(E25)
NG
• Replace the harness.
• Replace the cooling water temperature sensor.
NG
• Check if the harness is damaged, or if the wiring is correct.
• Replace the harness.
OK
ReplaceE-ECU.
TNV_DI_SM_A4-Troubleshooting.book 159 ページ 2007年11月15日 木曜日 午後5時27分