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Home >> Subaru >> 2021 >> Forester Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System (Diagnostics) (2 Of 4) >> Diagnostic Procedure With Diagnostic Trouble Code (DTC) >> DTC P0604: Internal Control Module Random Access Memory (Ram) Error >> Notes
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DTC P0604: Internal Control Module Random Access Memory (Ram) Error: Notes

1. - 

DTC detecting condition: 

Immediately at fault recognition

Trouble symptom: 

NOTE: After the faulty parts are repaired or replaced, perform the final check in Basic Diagnostic Procedure. Ref. to ENGINE (DIAGNOSTICS) (H4DO)>BASIC DIAGNOSTIC PROCEDURE>PROCEDURE .
  1. CHECK DTC  .
    1. Turn the ignition switch to ON.
    2. Using the Subaru Select Monitor or a general scan tool, read the DTC of [Engine].

      Ref. to COMMON (DIAG)>DIAGNOSTIC TROUBLE CODE (DTC) .

    Is DTC other than P0604 displayed? (Current malfunction)

    Yes  : Check the appropriate DTC using the "Diagnostic Trouble Code (DTC)". Ref. to ENGINE (DIAGNOSTICS) (H4DO)>DIAGNOSTIC TROUBLE CODE (DTC) .

    No  : Even if DTC is detected, the circuit has returned to a normal condition at this time.

    Reproduce the failure, and then perform the diagnosis again.

    NOTE: In this case, temporary poor contact of connector, temporary open or short circuit of harness may be the cause.