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 standards, 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 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 DTC [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: P0604.

11. Check the DTC judgment result.





HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.
- If the judgment result sows INCOMPLETE or UNKNOWN, perform step [A] again.

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

13. Check the DTC judgment result.

HINT
- If the judgment result shows ABNORMAL, the system has a malfunction.
- If the judgment result shows NORMAL, the system is normal.

14. If the test result is INCOMPLETE or UNKNOWN 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. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

PROCEDURE

1. CHECK DTC

(a) Connect Techstream to the DLC3.

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

(c) Turn the Techstream on.

(d) Clear the DTC.

(e) Turn the engine switch off.

(f) Disconnect the negative battery terminal and wait for 1 minute.

(g) Connect the negative battery terminal.

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

(i) Wait 16 seconds or more.

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

(k) Read the DTCs.

Result:





B -- CHECK FOR INTERMITTENT PROBLEMS Check For Intermittent Problems

A -- REPLACE ECM Components