When replacing the ECU, always
check that the communication circuit is normal.
DIAGNOSTIC FUNCTION
WCM sets the diagnosis code No. B1A10, B1A11, B1A12, B1A13, B1A14, B1A15, B1A16, or B1A17 when
it receives low battery voltage signal from the transmitter.
JUDGEMENT CRITERIA
B1A10: WCM determines that the abnormality is present
when it receives low battery voltage signal from the transmitter 1 (the first transmitter registered
in WCM) five consecutive times.
B1A11: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 2 (the second transmitter registered in WCM) five consecutive times.
B1A12: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 3 (the third transmitter registered in WCM) five consecutive
times.
B1A13: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 4 (the fourth transmitter registered in WCM) five consecutive times.
B1A14: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 5 (the fifth transmitter registered in WCM) five consecutive
times.
B1A15: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 6 (the sixth transmitter registered in WCM) five consecutive
times.
B1A16: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 7 (the seventh transmitter registered in WCM) five consecutive times.
B1A17: WCM determines that the abnormality is present when it receives low battery
voltage signal from the transmitter 8 (the eighth transmitter registered in WCM) five consecutive times.
PROBABLE CAUSES
Battery failure in the transmitter
Malfunction of the transmitter
Malfunction of WCM
DIAGNOSTIC PROCEDURE
STEP 1. Replace the battery in the transmitter and recheck
the diagnosis code.
Replace the battery in the transmitter by which the diagnosis code is set with a new one,
and recheck if the diagnosis code is set.
(1)Replace the battery in the transmitter by which the diagnosis code is set.
(2)Use the transmitter to lock/unlock the doors.
(3)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Go to Step 2.
The diagnosis is complete (Discharged battery).
STEP 2. Replace the transmitter and recheck the diagnosis code.
Replace the transmitter by which the diagnosis code is set with a new one, register the
encrypted code and the keyless entry secret code (Refer to ), and
recheck if the diagnosis code is set.
(1)Use the transmitter to lock/unlock the doors.
(2)Check if the diagnosis code is set.
Q.
Is the diagnosis code set?
Replace WCM and register the ID codes (Refer to ).