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Home >> Toyota >> 2009 >> Matrix S, AWD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 3 (Engine Control System (2ZR-FE)) >> SFI System >> DTC P0604 Random Access Memory (RAM) >> 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 standards, the ECM will illuminate the MIL and set the DTC immediately.

DTC DETECTION CONDITION CHART

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