Subaru Tribeca B9 P0021 Intake Camshaft Over-Advanced Symptom

The P0021 trouble code is confirmed when the ECM detects that the Bank 2 intake camshaft position is more advanced than the commanded target value. Verification involves using an OBD2 scan tool to monitor real-time data for 'AVCS intake left' or 'Bank 2' timing parameters while the engine is running. A discrepancy where the actual camshaft angle consistently exceeds the target angle under varying RPM conditions indicates the symptom is present.

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