DTC P0604 Random Access Memory (RAM): Description
WARNING: This page is about a different car, the 2007 Lexus SC 430. However, it is still accessible from the selected car via links, so may be relevant.
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 standards, the ECM will illuminate the MIL and set a DTC immediately.
DTC DETECTION CONDITION CHART
| DTC No. | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0604 | ECM RAM errors | ECM |