Last Modified: 05-13-2024 6.11:8.1.0 Doc ID: RM100000001HT45
Model Year Start: 2020 Model: Corolla Prod Date Range: [03/2019 - 09/2022]
Title: 2ZR-FAE (ENGINE CONTROL): SFI SYSTEM: P0604; Random Access Memory (RAM); 2020 - 2022 MY Corolla [03/2019 - 09/2022]

DTC

P0604

Random Access Memory (RAM)

MONITOR DESCRIPTION

The ECM continuously monitors its internal memory status. This self-check ensures that the ECM is functioning properly. This 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 this DTC.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

MIL

Memory

Note

P0604

Random Access Memory (RAM)

ECM RAM error (1 trip detection logic).

ECM

Comes on

DTC stored

DTC for Mexico Models

- Applies

MONITOR STRATEGY

Related DTCs

P0604: Internal control module random access memory error (RAM error on electronic throttle control)

Required Sensors/Components (Main)

ECM

Required Sensors/Components (Related)

-

Frequency of Operation

Continuous

Duration

6 times

MIL Operation

Immediate

Sequence of Operation

None

TYPICAL ENABLING CONDITIONS

Monitor runs whenever the following DTCs are not stored

None

TYPICAL MALFUNCTION THRESHOLDS

RAM mirror check

Fail

CONFIRMATION DRIVING PATTERN

  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the Techstream on.
  4. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure).
  5. Turn the Techstream off.
  6. Turn the ignition switch off.
  7. Disconnect the Techstream.
  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 Techstream to the DLC3.
  11. Turn the ignition switch to ON.
  12. Turn the Techstream on.
  13. Wait 16 seconds or more.
  14. Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
  15. Read the pending DTCs.

    HINT:

    • If a pending DTC is output, the system is malfunctioning.
    • If a pending DTC is not output, perform the following procedure.
  16. Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
  17. Input the DTC: P0604.
  18. Check the DTC judgment result.

    Techstream 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

    HINT:

    • If the judgment result shows NORMAL, the system is normal.
    • If the judgment result shows ABNORMAL, the system has a malfunction.
  19. If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs.

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    HINT:

    • If a permanent DTC is output, the system is malfunctioning.
    • If no permanent DTC is output, the system is normal.

CAUTION / NOTICE / HINT

NOTICE:

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.

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HINT:

Read Freeze Frame Data using the Techstream. The ECM records vehicle and driving condition information as Freeze Frame Data the moment a DTC is stored. 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.

CLEAR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear the DTCs.

Powertrain > Engine and ECT > Clear DTCs

(e) Turn the ignition switch off.

NEXT

2.

READ OUTPUT DTC (DTC P0604)

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

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

(c) Turn the ignition switch to ON.

(d) Turn the Techstream on.

(e) Wait for 16 seconds or more.

(f) Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.

(g) Read the DTCs.

Powertrain > Engine and ECT > Trouble Codes

Result

Proceed to

DTCs are not output

A

DTC P0604 is output

B
A

CHECK FOR INTERMITTENT PROBLEMS

B

REPLACE ECM