When the diagnosis
code No. B1A24 is set, be sure to diagnose the CAN bus line.
When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSIS FUNCTION
ETACS-ECU sets the diagnosis code No. B1A24 when the key ID was not registered in it.
JUDGMENT CRITERIA
ETACS-ECU determines that the abnormality is present, if the ignition key’s key
ID is not registered in ETACS-ECU when the ignition switch is turned ON.
PROBABLE CAUSES
Malfunction of CAN bus line
Key ID not registered
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. Register the key ID and recheck the diagnosis code.
Register the key ID of the ignition key by which the diagnosis code is set (Refer to ),
and recheck if the diagnosis code is set.
(1)Register the ignition key which is used when detect the diagnosis code.
(2)Remove the ignition key from the cylinder and then insert the ignition key again.
(3)After 2 or 3 seconds later from inserting the key, then turn the ignition ON.
(4)Check if the diagnosis code is set?
Q.
Is the diagnosis code set?
Replace ETACS-ECU and register the ID codes (Refer to ).
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting 
).