P0604
3UZ-FE 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. This 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
- Connect the Techstream to the DLC3.
- Turn the ignition switch to ON and turn the Techstream on.
- Clear DTCs (even if no DTCs are stored, perform the clear DTC operation).
- Turn the ignition switch off and wait for at least 30 seconds.
- Turn the ignition switch to ON and turn the Techstream on [A].
- Wait 16 seconds or more.
- Enter the following menus: Powertrain / Engine / Trouble Codes [B].
- Read the DTCs.
HINT
- If a DTC is output, the system is malfunctioning.
- If a DTC is not output, perform the following procedure.
- Enter the following menus: Powertrain / Engine / Utility / All Readiness.
- Input the DTC: P0604.
- Check the DTC judgment result.
HINT
If the judgment result shows ABNORMAL, the system has a malfunction.
- 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.
INSEPCTION PROCEDURE
PROCEDURE
1. CHECK DTC
(a) Clear DTCs.
(b) Turn the ignition switch OFF.
(c) Disconnect the cable from the negative battery terminal and wait for 1 minute.
(d) Connect the cable to the negative battery terminal.
(e) Turn the ignition switch to ON.
(f) Read the DTCs.
OK:
P0604 is not present.
NG -- REPLACE ECM Service and Repair
OK -- CHECK FOR INTERMITTENT PROBLEMS