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DTC B1A28 ECM authentication error
 
 
caution
  • When DTC B1A28 is set, be sure to diagnose the CAN bus line.
  • When replacing the ECU, always check that the communication circuit is normal.
 
 
DIAGNOSTIC FUNCTION
ETACS-ECU sets DTC B1A28 when the ETACS-ECU's key certification result and the engine control module's starting condition do not match.
 
 
JUDGMENT CRITERIA
ETACS-ECU determines that the abnormality is present, if the key certification result OK but engine control module prohibits engine start by immobilizer function or key certification result NG but engine permits engine starts.
 
 
TROUBLESHOOTING HINTS
  • The CAN bus line may be defective.
  • The ETACS-ECU may be defective.
  • The engine control module may be defective.
  • Chassis number registered in ECM unmatched
  • Chassis number registered in ETACS-ECU unmatched
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), read the DTC again.
Check again if the DTC is set in ETACS-ECU.
(1)
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-IIISE).
Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE) ."
(2) Erase the DTC.
(3) Remove the ignition key from key cylinder and insert it again then turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(4) On completion, check that the DTC is not set again.
Is the DTC set?
Go to Step 2.
There is an intermittent malfunction such as poor engaged connector(s) or open circuit (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
 
STEP 2. Using scan tool (M.U.T.-IIISE), diagnose the CAN bus line.
(1) Connect scan tool (M.U.T.-IIISE). Refer to "How to connect the Scan Tool (M.U.T.-IIISE) ."
(2) Turn the ignition switch to the "ON" position.
(3) Diagnose the CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is the CAN bus line found to be normal?
Go to Step 3.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
 
STEP 3. Using scan tool (M.U.T.-IIISE), read the other system DTC.
Check whether an engine-related DTCs is set.
Is the DTC set?
Perform troubleshooting for the ECM (Refer to GROUP 13A - Troubleshooting ).
Go to Step 4.
 
STEP 4. Using scan tool (M.U.T.-IIISE), read the other system DTC.
Is DTC B1761 or B2206 set?
Proceed to DTC B1761 (Chassis No. not programmed) or DTC B2206 (Chassis No. mismatch) (Refer to <B1761>, <B2206>).
Go to Step 5.
 
STEP 5. Using scan tool (M.U.T.-IIISE), read the DTC again.
Check again if the DTC is set.
(1) Register the ignition key which is used when detect the DTC.
(2) Remove the ignition key from the cylinder and then insert the ignition key again.
(3) After 2 or 3 seconds later from inserting the key, then turn the ignition "ON".
(4) Check if the DTC is set.
Is the DTC set?
Replace ETACS-ECU (Refer to ) and register the ID codes (Refer to ).
The diagnosis is complete.