P0020 on Subaru: How to Diagnose & Fix
Camshaft Position 'A' Actuator Circuit (Bank 2)
1 Subaru model · 1 documented issue · $150-$500 repair
P0020 on Subaru by model: symptoms, diagnosis and fix
The Active Valve Control System (AVCS) solenoids on the EJ257 engine are prone to failure from oil contamination and carbon buildup. When they stick or fail, the ECU cannot properly adjust camshaft timing, causing rough idle, hesitation, and reduced power. The solenoids are oil-controlled and degrade faster with extended oil change intervals or contaminated oil.
Common Symptoms
- Check engine light with AVCS-related codes
- Rough or hunting idle
- Hesitation on acceleration
- Reduced power in mid-range RPMs
- Occasional stalling at idle
How to Fix
Replace the failed AVCS solenoid(s) — there are two on the EJ257, one per bank ($80-$150 each for parts). Clean the oil passages feeding the solenoids during replacement. Use OEM Subaru solenoids for reliability. Prevent future failures by using quality synthetic oil and changing every 3,000-4,000 miles under hard driving conditions. Some owners clean solenoids with brake cleaner as a temporary fix.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Subaru 10921AA020 Intake AVCS Oil Control Valve
early intake OCV only after that valve fails electrical/hydraulic response testing Fitment/availability: EJ257 model years 2004-2006 intake AVCS position; sold individually, confirm VIN and bank Fitment/availability: In stock and ready t…
- Genuine Subaru 10921AA080 Intake AVCS Oil Control Valve
middle intake OCV branch only after that valve fails electrical/hydraulic response testing Fitment/availability: EJ257 model years 2006-2010 intake AVCS position; overlap years require VIN confirmation, sold individually Fitment/availabi…
- Genuine Subaru 10921AA140 Intake AVCS Oil Control Valve
late intake OCV branch only after that valve fails electrical/hydraulic response testing Fitment/availability: EJ257 model years 2010-2021 intake AVCS position; overlap years require VIN confirmation, sold individually Fitment/availabili…
- Genuine Subaru 10917AA060 Right Exhaust AVCS Oil Control Valve and Holder
right exhaust valve/holder assembly only after right exhaust response or contamination failure is proven Fitment/availability: EJ257 model years 2008-2021 right-hand exhaust AVCS position only; confirm VIN Fitment/availability: In stock …
- Genuine Subaru 10917AA070 Left Exhaust AVCS Oil Control Valve and Holder
left exhaust valve/holder assembly only after left exhaust response or contamination failure is proven Fitment/availability: EJ257 model years 2008-2021 left-hand exhaust AVCS position only; confirm VIN Fitment/availability: In stock and…
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Owner tips & cautions
- TipClean your AVCS solenoids every 30,000 miles as preventive maintenance. Remove them, spray with brake cleaner, and reinstall. Takes 20 minutes per side.
- TipShort oil change intervals (3,000-4,000 miles) with quality synthetic oil are the best prevention. The EJ257 is hard on oil and dirty oil kills AVCS solenoids.
P0020 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0020 mean on a Subaru?
P0020 stands for "Camshaft Position 'A' Actuator Circuit (Bank 2)." P0020 is a generic powertrain code indicating a fault in the camshaft position (intake/'A') actuator circuit on bank 2 — the side of the engine that does not contain cylinder number one. The engine computer controls a variable valve timing (VVT) solenoid to advance or retard camshaft timing for efficiency and power; this code sets when it detects an electrical problem in that solenoid's control circuit. The result can be reduced performance, rough running, or poor fuel economy. It is usually not an immediate breakdown risk but should be diagnosed to prevent driveability and timing issues. On Subaru it is documented across 1 model: WRX STI.
What are the most common causes of P0020?
The most common causes of P0020 are: Faulty bank 2 camshaft (VVT/oil control) solenoid, Wiring or connector damage to the VVT solenoid, Low or dirty engine oil restricting VVT operation, Clogged VVT solenoid screen/oil passage, Open or short in the actuator control circuit, Failed PCM/ECM (rare). The specific cause varies by vehicle.
How much does it cost to fix P0020 on a Subaru?
Published repair estimates on Subaru range from $150 to $500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0020 on a different make?
View P0020 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.