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Home >> Lexus >> 2007 >> RX 400h AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 296 (Engine Control System) >> SFI System >> DTC P0604 Random Access Memory (RAM) >> Monitor Description
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Monitor Description

WARNING: This page is about a different car, the 2008 Toyota FJ Cruiser. 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. 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 the DTC immediately.

DTC DETECTION CONDITION

DTC No. DTC Detection Condition Trouble Area
P0604 ECM RAM errors ECM