Before replacing
the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit
are normal.
When the ETACS-ECU of vehicles without KOS is replaced, the encrypted code of the ignition
key needs to be registered to the ETACS-ECU. (If the encrypted code is not registered, the engine
cannot be started. Register the encrypted code as described in Immobilizer System - How
to Register Key ID .)
DIAGNOSTIC FUNCTION
When the LDW-ECU receives incorrect vehicle information from the ETACS-ECU, diagnosis
code No. C1707 will be stored.
JUDGEMENT CRITERIA
When the LDW-ECU detects the ETACS-ECU coding data below consecutively five times (for
2.5 seconds or more), the LDW-ECU will determines that the system is defective.
"LDW equipment status": Not Present
"LDW Parameter status": Not parameter
"LDW production setup status": Not Present
PROBABLE CAUSES
Malfunction of the CAN bus line.
Malfunction of the ETACS-ECU (you have substituted another ECU from a different
vehicle, or the coding data is incorrect).
Malfunction of the LDW-ECU
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to diagnose the CAN bus lines.
Q.
Is the check result normal?
Go to Step 2
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
On completion, go to Step 2.
STEP 2. M.U.T.-III other system diagnosis code
Check if the ETACS diagnosis code is set.
Q.
Is the diagnosis code set?
Perform troubleshooting for ETACS (Refer to GROUP 54A - ETACS - Troubleshooting ).
Go to Step 3
STEP 3. Check the coding data in the ETACS-ECU.
(1)Use M.U.T.-III to read out the coding data in ETACS-ECU. (Refer to GROUP 00 - Precautions before
Service - Coding Reference Table .)
(2)Check the followings:
"LDW equipment status" is set to a correct value ("Type B").
"LDW Parameter status" is set to a correct value ("Type 5" or "Type 6").
"LDW production setup status" is set to a correct value ("Type B").
Q.
Is the check result normal?
Go to Step 4
Replace with the coded ETACS-ECU, and then go to Step 4.
STEP 4. Check whether the diagnosis code is reset.
Recheck if the diagnosis code No. C1707 is set.
(1)Erase the diagnosis code.
(2)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace the LDW-ECU.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunction ).
.)
