LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2010 >> GS 450h >> Repair and Diagnosis (Single Page) >> Engine Performance >> Testing & Diagnosis >> Engine Control System (Diagnostic Codes (P0365-U0293) & Circuit Tests) >> SFI System >> DTC P0604: Internal Control Module Random Access Memory (RAM) Error >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0604: Internal Control Module Random Access Memory (RAM) Error: Procedure

  1. CHECK ANY OTHER DTCS OUTPUT (IN ADDITION TO DTC P0604) 
    1. Connect the Techstream to the DLC3.
    2. Turn the power switch on (IG).
    3. Turn the Techstream on.
    4. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
    5. Read the DTCs.

      Result

      Display (DTC Output) Proceed to
      P0604 A
      No output B

    B → See step   2 

    A → See step   3 

  2. CHECK FOR INTERMITTENT PROBLEMS. Refer to CHECK FOR INTERMITTENT PROBLEMS 
  3. REPLACE ECM. Refer to REMOVAL