When diagnosis
code No. B1770 is set, be sure to diagnose the CAN bus line.
When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSIS FUNCTION
If incorrect vehicle information data is received, KOS-ECU sets the diagnosis code No.
B1770.
JUDGEMENT CRITERIA
If incorrect global coding data is received with the ignition switch turned ON when the
coding confirmation is completed, KOS-ECU determines that there is a problem.
PROBABLE CAUSES
Malfunction of CAN bus line
Malfunction of KOS-ECU
Malfunction of ETACS-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 ).
STEP 2. M.U.T.-III other system diagnosis code
Check if a coding-related diagnosis code is set in the ETACS-ECU.
Q.
Is the diagnosis code set?
Perform troubleshooting for ETACS-ECU (Refer to GROUP 54A - ETACS - Troubleshooting ).
Go to Step 3.
STEP 3. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set.
(1)Turn the engine switch from the LOCK (OFF) position to the ON position.
(2)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Check if the coding data is sent for the vehicles with immobilizer function on
"non-adaptable" condition. If so, change the immobilizer function into "adaptable", and then
go to Step 4.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection
Service Points - How to Cope with Intermittent Malfunction ).
STEP 4. Check whether the diagnosis code is reset.
Recheck if the diagnosis code is set.
(1)Turn the engine switch from the LOCK (OFF) position to the ON position.
(2)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace KOS-ECU and register the ID codes (Refer to ).
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting 
).