DTC P0021 "A" Camshaft Position - Timing Over-Advanced Or System Performance Bank 2: Notes

DTC detecting condition:

Detected when two consecutive driving cycles with fault occur.

Trouble symptom:

Engine stalls.
Improper idling
CAUTION: After servicing or replacing faulty parts, perform Clear Memory Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Clear Memory Mode>OPERATION . and Inspection Mode Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Inspection Mode>PROCEDURE .

IDENTIFYING FAULTY PART.
1. Clear the memory. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Clear Memory Mode .
2. Replace the defective oil control solenoid by the other (RH or LH, intake side or exhaust side) oil control solenoid. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>Oil Control Solenoid .
3. Perform appropriate drive cycle test. Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Drive Cycle .
4. Check that the fault occurrence (DTC and incorrect advancing) has shifted to the other location.
Did the detected DTC shift to the location where the oil control solenoid was replaced?
- Yes : Replace the faulty oil control solenoid. Ref. to FUEL INJECTION (FUEL SYSTEMS) (H4DOTC)>Oil Control Solenoid .
- No : Go to 2.
CHECK CURRENT DATA.
1. Start the engine and let it idle.
2. Using the Subaru Select Monitor, read the value in [VVT Adv. Ang. Amount L].
  NOTE: For detailed procedures, refer to "Data Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Subaru Select Monitor .
Is the value of [VVT Adv. Ang. Amount L] approx. 27 deg?
- Yes : Go to 3.
- No : Check the following item and repair or replace if necessary.
  - Intake cam sprocket (clog or dirt of oil routing, setting of spring)
  - Intake camshaft (dirt, damage of camshaft)
CHECK CURRENT DATA.
1. Drive with acceleration and deceleration at 80 km/h (50 MPH) or less.
  NOTE: Drive to an extent that the duty output of oil flow control solenoid valve increases.
2. Using the Subaru Select Monitor, read the values in [OCV Duty L] and [VVT Adv. Ang. Amount L].
  NOTE: For detailed procedures, refer to "Data Monitor". Ref. to ENGINE (DIAGNOSTICS) (H4DOTC)>Subaru Select Monitor .
When the value of [OCV Duty L] increases from 10%, is the value of [VVT Adv. Ang. Amount L] approx. 27 deg?
- Yes : Check the following item and repair or replace if necessary.
  - Intake cam sprocket (clog or dirt of oil routing, setting of spring)
  - Intake camshaft (dirt, damage of camshaft)
- No : Perform the following procedures, and clean the oil routing.
  Replace the engine oil and idle the engine for 5 minutes, and then replace the oil filter and engine oil. Ref. to LUBRICATION(H4DO)>Engine Oil>REPLACEMENT . Ref. to LUBRICATION(H4DO)>Engine Oil Filter .