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, B1A09, B1A0A or B1A0B.
JUDGMENT 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.
(1)Synchronise the rolling codes as follows:
Push the lock switch or unlock switch of keyless operation key twice or more.
When the keyless operation is not recovered after performing the above procedure,
register the key again (refer to ).
(2)Recheck if the diagnosis code is set.
.....
Push the lock switch or unlock switch of keyless operation key.
.....
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 key (refer to ), and then check whether the diagnosis
code is set again.
(1)Push the lock switch or unlock switch of keyless operation key.
(2)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace KOS-ECU and register the ID codes (Refer to ).