When replacing the ECU, always check that the communication circuit is normal.
DIAGNOSIS FUNCTION
If no keyless operation key ID is registered with KOS&OSS-ECU, or a keyless operation key with unregistered ID is used, the KOS&OSS-ECU sets 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 KOS&OSS-ECU
DIAGNOSIS PROCEDURE
STEP 1. Register the key ID.
Refer to the separate manual "How to register an ID" to register the keyless operation key ID.
Q.
Is the key ID registration complete?
Go to Step 2.
Troubleshoot for the relevant diagnosis code No.B2400 (Refer to ).
STEP 2. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set in the KOS&OSS-ECU.
Q.
Is the diagnosis code set?
Replace KOS&OSS-ECU and register the ID codes (Refer to ).
Troubleshoot for the relevant diagnosis code No.B2400 (Refer to 
).