Code No.B1A28 ENG.ECU authenticate error


DIAGNOSIS FUNCTION


WCM sets diagnosis code No. B1A28 when the WCM’s key certification result and the engine-ECU’s starting condition do not match.

JUDGEMENT CRITERIA


WCM determines that the abnormality is present, if the key certification result and the engine-ECU’s starting condition do not match after the engine start permission communication is completed.

PROBABLE CAUSES



DIAGNOSIS PROCEDURE


STEP 1. Check if chassis number registered in the engine-ECU matches with the vehicle’s chassis number.


Check if chassis number registered in the engine-ECU matches with the vehicle’s chassis number.

Q. Do chassis number registered in the engine-ECU and the vehicle’s chassis number match?

Go to Step 2.

Replace the engine-ECU and record chassis number (Refer to GROUP 00 - How to Perform Chassis Number (Chassis No.) Writing ). Record chassis number and go to Step 2 .

STEP 2. Check whether the diagnosis code is reset.


Recheck if the diagnosis code is set.
(1)Turn the ignition switch from the LOCK (OFF) position to the ON position.
(2)Check if the diagnosis code is set.

Q. Is the diagnosis code set?

Replace WCM and register the ID codes (Refer to ).

Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Deal with Intermittent Malfunction ).