SFI SYSTEM, Diagnostic DTC:P0604

DTC Code DTC Name
P0604 Random Access Memory (RAM)

DESCRIPTION

The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is functioning properly. The ECM memory status is diagnosed by internal "mirroring" of the main CPU and sub CPU to detect Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the standard, the ECM will illuminate the MIL and store a DTC immediately.

DTC No. DTC Detection Condition Trouble Area
P0604 ECM RAM errors (Main CPU and sub CPU mirroring failure) (1 trip detection logic). ECM

MONITOR STRATEGY

Required sensors/Components ECM
Frequency of operation Continuous

CONFIRMATION DRIVING PATTERN

Note

After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.


  1. Connect the intelligent tester to the DLC3.

  2. Turn the ignition switch to ON and turn the tester on.

  3. Clear DTCs (even if no DTCs are stored, perform the clear DTC procedure).

  4. Turn the tester off.

  5. Turn the ignition switch off.

  6. Disconnect the tester.

  7. Disconnect the cable from the negative (-) battery terminal and wait for 1 minute.

  8. Connect the cable to the negative (-) battery terminal.

  9. Connect the tester to the DLC3.

  10. Turn the ignition switch to ON and turn the tester on.

  11. Wait 16 seconds or more.

  12. Enter the following menus: Powertrain / Engine and ECT / DTC.

  13. Read pending DTCs.

    Tech Tips


    • If a pending DTC is output, the system is malfunctioning.

    • If a pending DTC is not output, perform the following procedure.

  14. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.

  15. Input the DTC: P0604.

  16. Check the DTC judgment result.

    Tester Display Description
    NORMAL

    • DTC judgment completed

    • System normal
    ABNORMAL

    • DTC judgment completed

    • System abnormal
    INCOMPLETE

    • DTC judgment not completed

    • Perform driving pattern after confirming DTC enabling conditions
    N/A

    • Unable to perform DTC judgment

    • Number of DTCs which do not fulfill DTC preconditions has reached ECU memory limit

    Tech Tips


    • If the judgment result shows NORMAL, the system is normal.

    • If the judgment result shows ABNORMAL, the system has a malfunction.

    • If the judgment result shows INCOMPLETE or N/A, perform the Confirmation Driving Pattern and the DTC judgment result again.

CAUTION / NOTICE / HINT

Note

After turning ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) battery terminal notices before proceeding with work Click here.

Tech Tips

Read freeze frame data using the intelligent tester. Freeze frame data records the engine conditions when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

PROCEDURE


  1. CHECK FOR DTC


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the tester on.

    4. Clear the DTCs Click here.

    5. Turn the tester off.

    6. Turn the ignition switch off.

    7. Disconnect the tester.

    8. Disconnect the cable from the negative (-) battery terminal and wait for 1 minute.

    9. Connect the cable to the negative (-) battery terminal.

    10. Connect the tester to the DLC3.

    11. Turn the ignition switch to ON and turn the tester on.

    12. Wait 16 seconds or more.

    13. Enter the following menus: Powertrain / Engine and ECT / DTC.

    14. Check for DTCs.

      OK
      P0604 is not output.

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

    REPLACE ECM Click here