Wireless Control Module
DTC B1A28: Engine control module authenticate errorCAUTION:
- When the 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 WCM.
- Engine control module malfunction.
- VIN registered in engine control module unmatched.
DIAGNOSIS
Required Special Tools:
MB991958: Scan Tool (M.U.T.-III Sub Assembly)
MB991824: Vehicle Communication Interface (V.C.I.)
MB991827: M.U.T.-III USB Cable
MB991910: M.U.T.-III Main Harness A (Vehicles with CAN communication system)
STEP 1. Using scan tool MB991958, diagnose the CAN bus line.
CAUTION: To prevent damage to scan tool (MB991958), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (MB991958).
1. Connect scan tool MB991958 to the data link connector.
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.
Q: Is the CAN bus line found to be normal?
YES : Go to Step 2.
NO : Repair the CAN bus line.
STEP 2. Check if VIN registered in the engine control module matches with the vehicle's VIN.
Check if VIN registered in the engine control module matches with the vehicle's VIN.
Q: Does the VIN registered in the engine control module match the vehicle's VIN?
YES : Go to Step 3.
NO : Replace the engine ECU and record VIN (Refer to General (Body and Chassis) - How to Perform Vehicle Identification Number (VIN) Writing). Record VIN and go to Step 3.
STEP 3. Recheck for diagnostic trouble code.
Check again if the DTC is set to the WCM.
1. Turn the ignition switch from the "LOCK" (OFF) position to the "ON" position.
2. Check if the DTC is set.
Q: Is the DTC set?
YES : Replace WCM and register the ID codes.
NO : Intermittent malfunction is suspected. (Refer to General (Body and Chassis) - How to Use Troubleshooting/Inspection Service Points - How to Deal with Intermittent Malfunction)