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DTC B1A28: Engine control module authenticate 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.
 
 
DTC SET CONDITION
WCM sets DTC B1A28 when the ignition key certification result and the engine control module starting condition do not match.
 
 
TECHNICAL DESCRIPTION (COMMENT)
WCM determines that the abnormality is present, if the key certification result and the engine control module starting condition do not match after the engine start permission communication is completed.
 
 
TROUBLESHOOTING HINTS
  • Malfunction of CAN bus line
  • Malfunction of WCM
  • Engine control module malfunction
  • VIN registered in engine control module unmatched
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
(1)
cautionTo prevent damage to scan tool (MB991958), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (MB991958).
Connect scan tool MB991958. Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(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 2.
Repair the CAN bus line (Refer to GROUP 54C, Diagnosis ).
 
STEP 2. Using scan tool MB991958, read the engine control module diagnostic trouble code.
Check again if the DTC is set in the engine control module.
Is the DTC set?
Troubleshoot the MFI system (Refer to GROUP 13A, Diagnostic trouble code chart <2.0L ENGINE> or GROUP 13C, Diagnostic trouble code chart <2.4L ENGINE>).
Go to Step 3.
 
STEP 3. Using scan tool MB991958, read the diagnostic trouble code.
Check if the DTC is set in the WCM.
(1) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(2) Check if the DTC is set.
Is DTC B1761 or B2206 set other than B1A28?
Perform the troubleshooting for each DTC. Refer to <B1761> and <B2206>.
Go to Step 4.
 
STEP 4. Recheck for diagnostic trouble code.
Check again if the DTC is set in the WCM.
(1) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(2) Check if the DTC is set.
Is the DTC set?
Replace WCM and register the ID codes (Refer to ). Then go to Step 5.
The diagnosis is complete.
 
STEP 5. Recheck for diagnostic trouble code.
Check again if the DTC is set in the WCM.
(1) Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
(2) Check if the DTC is set.
Is the DTC set?
Replace the engine control module and record VIN (Refer to GROUP 00 - How to Perform Vehicle Identification Number (VIN) Writing ).
The procedure is complete.