caution | Before replacing the ECU,
ensure that the communication circuit is normal. |
DIAGNOSIS PROCEDURE |
STEP 1. Resistance measurement at the column switch connector |
(1)Disconnect the connector, and measure at the wiring harness side. |
(2)Measure the resistance between the column switch connector (earth terminal) and
the body earth. OK: Continuity exists (2 Ω or less) |
Q.
Is the check result normal?
|
Go to Step 3. |
|
Go to Step 2. |
|
STEP 2. Check of open circuit in body earth line between column switch connector (earth terminal) and the body earth. |
Q.
Is the check result normal?
|
The trouble can be an intermittent malfunction (Refer to GROUP 00 -
How
to use Troubleshooting/inspection Service Points -
How to Cope with Intermittent Malfunction). |
|
Repair the connector(s) or wiring harness. |
|
STEP 3. Voltage measurement at the column switch connector. |
(1)Disconnect the connector, and measure at the wiring harness side. |
(2)Measure the voltage between the column switch connector (power supply terminal)
and the body earth. OK: System voltage |
Q.
Is the check result normal?
|
Go to Step 5. |
|
Go to Step 4. |
|
STEP 4. Check of short to power supply, short to earth, and open circuit in BUP1 line between ETACS-ECU connector and column switch connector. |
Q.
Is the check result normal?
|
The trouble can be an intermittent malfunction (Refer to GROUP 00 -
How
to use Troubleshooting/inspection Service Points -
How to Cope with Intermittent Malfunction). |
|
Repair the connector(s) or wiring harness. |
|
STEP 5. Check of open circuit in DATA line between ETACS-ECU connector and column switch connector. |
Q.
Is the check result normal?
|
Go to Step 6. |
|
Repair the connector(s) or wiring harness. |
|
STEP 6. Check whether the diagnosis code is set again. |
Check again if the diagnosis code is set in the ETACS-ECU. |
(1)Erase the diagnosis code. |
(2)Turn the ignition switch from "LOCK" (OFF) position to "ON" position. |
(3)Check if diagnosis code is set. |
Q.
Is the diagnosis code set?
|
Replace the column switch assembly. |
|
A poor connection, open circuit, or other intermittent malfunctions in the LIN
bus lines between the column switch and the ETACS-ECU (Refer to GROUP 00 -
How to Cope with
Intermittent Malfunction). |
|