FAILURE DIAGNOSIS
TNV DI Service Manual
1-173
Method and Procedure of Failure Diagnosis
3. Check of harness continuity:
• Remove the rack actuator relay from the harness, and remove E-ECU from the harness.
• Check the harness continuity using a circuit tester.
4. Movement check of the relay:
• 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 (rack actuator relay, E-
ECU).
• Connect the diagnosis tool, and log in to the diagnosis tool after key switch turning-on.
• Activate the rack actuator relay by the diagnosis tool “Diagnosis Test: Active control”, and measure the
voltage between terminals E33 and E45.
Terminal
Continuity
Status
Relay coil (downstream side) E33
[Between E-ECU and sensor connector]
Available
OK: normal
Unavailable
NG: harness disconnection
Relay coil (upstream side) E07
[Between E-ECU and sensor connector]
Available
OK: normal
Unavailable
NG: harness disconnection
Between E33 and GND/E28/E45/E47
Unavailable
OK: normal
Available
NG: harness short-circuited with GND
Between E33 and E43/E48
Unavailable
OK: normal
Available
NG: Harness short-circuited with power
supply
NG
• Check if the harness is damaged, or if the wiring is correct.
• Replace the harness.
OK
Check the movement of the rack actuator relay by the diagnosis tool.
→
ON/OFF setting status
Voltage
Status
ON
1.75[V] and below OK: normal
Over 1.75[V]
NG: Harness short-circuited with power supply or E-
ECU fault
OFF
2.5[V] and above
OK: normal
Under 2.5[V]
NG: Harness short-circuited with GND or E-ECU fault
NG
• Check if the harness is damaged, or if the wiring is correct.
• Replace the harness.
OK
Replace the E-ECU.
TNV_DI_SM_A4-Troubleshooting.book 173 ページ 2007年11月15日 木曜日 午後5時27分