P0604

1UR-FSE ENGINE CONTROL SYSTEM: SFI SYSTEM: P0604: Random Access Memory (RAM)
P0604 - Random Access Memory (RAM)

DESCRIPTION

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





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





CONFIRMATION DRIVING PATTERN





1. Connect the Techstream to the DLC3.

2. Turn the engine switch on (IG) and turn the Techstream on.

3. Clear the DTCs (even if no DTCs are stored, perform the clear DTC procedure) Reading and Clearing Diagnostic Trouble Codes.

4. Turn the engine switch off and wait for at least 30 seconds.

5. Turn the engine switch on (IG) and turn the Techstream on [A].

6. Wait 16 seconds or more.

7. Enter the following menus: Powertrain / Engine / Trouble Codes.

8. Read the DTCs [B].

HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.

9. Enter the following menus: Powertrain / Engine / Utility / All Readiness.

10. Input the DTC: P060A.

11. Check the DTC judgment result.





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

12. If the test result is INCOMPLETE or N/A and no DTC is output, perform a universal trip and check for permanent DTCs Reading and Clearing Diagnostic Trouble Codes.

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

INSPECTION PROCEDURE

HINT
Read freeze frame data using the Techstream. Freeze frame data records the engine condition 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 DTC

(a) Clear DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the engine switch off.

(c) Disconnect the battery negative terminal and wait for 1 minute Service Precautions.

(d) Connect the battery negative terminal Service Precautions.

(e) Turn the engine switch on (IG).

(f) Connect the Techstream to the DLC3.

(g) Turn the Techstream on.

(h) Wait 16 seconds or more.

(i) Enter the following menus: Powertrain / Engine / Trouble Codes.

(j) Check DTC.

OK:

P0604 is not present.

NG -- REPLACE ECM Removal

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems