DTC B2401: Keyless/KOS key ID not registered: Diagnosis

Required Special Tools:

MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicles 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?
1. YES: Go to Step 2.
2. NO: Repair the CAN bus line. (Refer to DIAGNOSIS ).
  
  Fig 1: Connecting Scan Tool MB991958 To Data Link Connector
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 2. Register the keyless operation key ID and recheck the diagnostic trouble code.
Register the keyless operation key ID (Refer to ID CODES REGISTRATION PROCEDURES ), and check whether the DTC is reset.
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?
1. YES: Go to Step 3.
2. NO: The procedure is complete.
STEP 3. Replace the keyless operation key and recheck the diagnostic trouble code.
Replace the keyless operation key for which the DTC is set with a new one, register the encrypted code and keyless operation key ID (Refer to ID registration procedure manual - ID codes registration judgement table), and check whether the DTC is reset.
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?
1. YES: Replace KOS-ECU and register the ID codes (Refer to ID registration procedure manual - ID codes registration judgement table).
2. NO: The procedure is complete.