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DTC B1A28 ENG ECU authentification error
 
 
caution
  • If DTC B1A28 is set, diagnose the CAN bus lines.
  • When replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
When the KOS&OSS-ECU certification result is different from the engine status after the completion of engine starting permission communication, KOS&OSS-ECU determines that a problem has occurred, and sets DTC B1A28. At the same time, KOS&OSS-ECU displays the immobilizer certification system inspection warning to the combination meter.
 
 
JUDGMENT CRITERIA
Check Conditions
  • At engine starting certification
Judgment Criterion
  • Certification result unmatch is received from ECM.
 
 
PROBABLE CAUSES
  • Writing error of chassis number to ECM (ECM has been interchanged between two vehicles, or chassis number has not been written after ECM replacement)
  • Malfunction of the CAN bus line
  • Malfunction of KOS&OSS-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line
Use the scan tool (M.U.T.-IIISE) to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Diagnosis ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), check the DTC.
Check if KOS&OSS-ECU DTC B1161 is set.
Is the DTC set?
Troubleshoot for the relevant DTC (Refer to ).
Go to Step 3.
 
STEP 3. Using scan tool (M.U.T.-IIISE), check the other system DTC.
(1) Check that the vehicle power can be turned ON and engine is started.
(2) Check the DTC of ECM.
Is the DTC set?
Troubleshoot the ECM (Refer to GROUP 13A - Diagnosis ). Then go to Step 4.
Go to Step 4.
 
STEP 4. Check whether the DTC is set again.
(1) Operate the engine switch several times within five seconds without depressing the brake pedal to turn ON and OFF the power supply mode.
(2) Check again if the DTC is set in the KOS&OSS-ECU.
Is the DTC set?
Replace the KOS&OSS-ECU and register the ID codes (Refer to ). Then go to Step 5.
Intermittent malfunction is suspected (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 5. Check whether the DTC is set again.
Check again if the DTC is set in the KOS&OSS-ECU.
Is the DTC set?
Replace the ECM (Refer to GROUP 13A - ECM ).
The diagnosis is complete.