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Home >> Toyota >> 2015 >> Prius One >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 17 (Engine Control System (Diagnostic Codes (P0300-P0657)) (Except Plug-In)) >> SFI System >> DTC P0604: Random Access Memory (RAM) [08/2014 - ] >> Monitor Description
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Monitor Description

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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 Random Access Memory (RAM) errors. If outputs from these CPUs are different and deviate from the standard, the ECM illuminates the MIL and stores the DTC immediately.

DTC No. DTC Detection Condition Trouble Area
P0604 ECM RAM error (1 trip detection logic). ECM