When replacing the ECU, always
check that the communication circuit is normal.
DIAGNOSTIC FUNCTION
The mechanism which automatically changes a code for lock/unlock each time a
lock operation is performed is referred to as a rolling code. If KOS-ECU receives wrong signal
(out of synchronisation of a rolling code) from the keyless operation key, KOS-ECU memorises
the diagnosis code No. B1A08.
JUDGEMENT CRITERIA
B1A08: If the difference between the rolling code for
the keyless operation key 1 (the first keyless operation key registered with KOS-ECU) and that memorised
by KOS-ECU is large, it is judged as abnormal.
B1A09: If the difference between the rolling code for the keyless operation key
2 (the second keyless operation key registered with KOS-ECU) and that memorised by KOS-ECU is
large, it is judged as abnormal.
B1A0A: If the difference between the rolling code for the keyless operation key
3 (the third keyless operation key registered with KOS-ECU) and that memorised by KOS-ECU is
large, it is judged as abnormal.
B1A0B: If the difference between the rolling code for the keyless operation key
4 (the fourth keyless operation key registered with KOS-ECU) and that memorised by KOS-ECU is
large, it is judged as abnormal.
PROBABLE CAUSES
Rolling code out of synchronisation
Malfunction of the keyless operation key
Malfunction of the KOS-ECU
DIAGNOSTIC PROCEDURE
STEP 1. Synchronise the rolling code and recheck the diagnosis
code.
Synchronise the rolling codes, 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)Press the lock or unlock switch of the keyless operation key for which the diagnosis
code is set at least once to synchronise the rolling codes.
(4)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Go to Step 2.
The diagnosis is complete.
STEP 2. Check whether the diagnosis code is reset.
Replace the keyless operation key for which the diagnosis code is set with a new one,
register the encrypted code 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 ).
The diagnosis is complete.
),
and check whether the diagnosis code is reset.