DTC 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.| DTC No. | DTC Detection Condition | Trouble Area |
| P0604 | ECM RAM errors (Main CPU and sub CPU mirroring failure) (1 trip detection logic). | ECM |
MONITOR STRATEGY
| Required sensors/Components | ECM |
| Frequency of operation | Continuous |
CONFIRMATION DRIVING PATTERN
- Connect the GTS to the DLC3.
- Turn the ignition switch to ON and turn the GTS on.
- Clear the DTCs (even if no DTCs are stored, perform the clear DTC operation).
- Turn the GTS off.
- Turn the ignition switch off.
- Disconnect the GTS.
- Disconnect the cable from the negative (-) battery terminal and wait for 1 minute.
- Connect the cable to the negative (-) battery terminal.
- Connect the GTS to the DLC3.
- Turn the ignition switch to ON and turn the GTS on.
- Wait 16 seconds or more.
- Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
- 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.
- Enter the following menus: Powertrain / Engine and ECT / Utility / All Readiness.
- Input the DTC: P0604.
- Check the DTC judgment result.
Tester 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.
- DTC judgment completed
- If the judgment result is INCOMPLETE or N/A and no pending DTC is output, perform a universal trip and check for permanent DTCs (LandCruiser RM000000VNG00DX.html).
- HINT:
- If a permanent DTC is output, the system is malfunctioning.
- If no permanent DTC is output, the system is normal.
INSPECTION PROCEDURE
- 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 (LandCruiser RM000000VNG00DX.html).
- HINT:
- Read freeze frame data using the GTS. 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.
| 1.CHECK FOR DTC |
Connect the GTS to the DLC3.
Turn the ignition switch to ON.
Turn the GTS on.
Clear the DTCs (LandCruiser RM000000VNG00DX.html).
Turn the GTS off.
Turn the ignition switch off.
Disconnect the GTS.
Disconnect the cable from the negative (-) battery terminal and wait for 1 minute.
Connect the cable to the negative (-) battery terminal.
Connect the GTS to the DLC3.
Turn the ignition switch to ON and turn the GTS on.
Wait 16 seconds or more.
Enter the following menus: Powertrain / Engine and ECT / Trouble Codes.
Check for DTCs.
- OK:
- P0604 is not output.
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| OK | ||
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