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DTC 2-1 EEPROM Communication Error: DTC 2-2 EEPROM Checksum Error: Description

These DTCs are output when an error occurs in the CPU of the mayday ECU assembly.

DTC DETECTION CONDITION

DTC No. DTC Detection Condition Trouble Area
2 - 1 Internal communication error in mayday ECU Mayday ECU assembly
2 - 2 Checksum error in mayday ECU Mayday ECU assembly

NOTICE: 

DTC REFERENCE

Current DTC Historic DTC only
Disconnect and reconnect battery. Check for current DTCs. If DTC returns, replace mayday ECU and mayday battery (backup battery). If this is only a historic DTC, the system has already recovered normally and should be operating normally. Clear historic DTCs.
  1. RESET MAYDAY ECU ASSEMBLY 
    1. Exit diagnosis mode and wait for 10 seconds.
    2. Disconnect the cable from the negative (-) battery terminal, and wait for 1 minute.
    3. Reconnect the cable to the negative (-) battery terminal, and wait for 10 seconds.
    4. Turn the ignition switch ON, and then check for the current DTC again.

    Result 

    RESULT REFERENCE

    Result Proceed to
    Current DTC 2-1 or 2-2 exists A
    Historic DTC 2-1 or 2-2 exists B

    B: CLEAR HISTORIC DTC 

    A: Go To Next Step 

  2. CHECK MAYDAY ECU ASSEMBLY 
    1. Press the "SERVICES" button and check the LEXUS Link condition with the LEXUS Link call center.

      OK: System operates normally. 

      NG: Current DTC 2-1 or 2-2 exists. 

    NG: REPLACE MAYDAY ECU ASSEMBLY TOGETHER WITH MAYDAY BATTERY AND THEN PERFORM  REGISTRATION  

    OK: END