P0604

2AR-FE ENGINE CONTROL: 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. 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.





MONITOR STRATEGY





TYPICAL ENABLING CONDITIONS





TYPICAL MALFUNCTION THRESHOLDS





CONFIRMATION DRIVING PATTERN

1. Connect the Techstream to the DLC3.

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

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

4. Turn the Techstream off.

5. Turn the ignition switch off.

6. Disconnect the Techstream.

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 Techstream to the DLC3.

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

11. Wait 16 seconds or more.

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

13. 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.

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

15. Input the DTC: P0604.

16. Check the DTC judgment result.





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

17. If the judgment result is INCOMPLETE or UNKNOWN and no pending DTC is output, perform a universal trip and check for permanent DTCs DTC Check / Clear.

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

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FOR DTC

(a) Connect the Techstream to the DLC3.

(b) Turn the ignition switch to ON.

(c) Turn the Techstream on.

(d) Clear the DTCs DTC Check / Clear.

(e) Turn the Techstream off.

(f) Turn the ignition switch off.

(g) Disconnect the Techstream.

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

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

(j) Connect the Techstream to the DLC3.

(k) Turn the ignition switch to ON and turn the Techstream on.

(l) Wait 16 seconds or more.

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

(n) Check for DTCs.

OK:

P0604 is not output.

NG -- REPLACE ECM Removal

OK -- CHECK FOR INTERMITTENT PROBLEMS Check for Intermittent Problems