If the diagnosis
code No. B2401 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 no keyless operation key ID is registered with KOS-ECU or if the keyless operation
key with ID not registered is used, KOS-ECU sets the diagnosis code No. B2401.
JUDGEMENT CRITERIA
If the number of the registered keyless operation keys is 0, or the registration of a
keyless operation key fails when the number of the registered keyless operation keys is 0, it
is judged as abnormal.
PROBABLE CAUSES
The registration of a keyless operation key ID fails when no keyless operation
key ID is registered.
Malfunction of the keyless operation key
Malfunction of KOS-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. Register the keyless operation key ID and recheck the diagnosis
code.
Register the keyless operation key ID (refer to ), and
check whether the diagnosis code is reset.
(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?
Go to Step 3.
The diagnosis is complete.
STEP 3. Replace the keyless operation key and recheck the diagnosis
code.
Replace the keyless operation key for which the diagnosis code is set with a new one,
register the key ID and keyless operation key ID (refer to ), and
check whether the diagnosis code is reset.
(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 KOS-ECU and register the ID codes (Refer to ).
Repair the CAN bus line (Refer to GROUP 54C -
Troubleshooting 
).
On completion, go to Step 2.