P0019 on 2020-2022 Subaru Impreza: Crankshaft-Camshaft Correlation Causes & Fixes

What's Unique About the 2020-2022 Subaru IMPREZA

On this specific generation of the Impreza with the 2.0L FB20D engine, the P0019 code has a well-documented history tied to software. Subaru issued Technical Service Bulletins (TSBs) acknowledging that the original ECM programming was overly sensitive and could trigger this code incorrectly. This makes it crucial for owners to check for an available software update before replacing any hardware, as a simple re-program at a dealership is often the complete and correct fix. 🎬 Watch: A quick overview of P0019 solutions for this engine. Many owners have reported that the dealer update resolved the code after they had already tried replacing parts.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light is on
• Rough or unstable idle
• Reduced engine power and poor acceleration
• Decreased fuel economy
• Engine may hesitate or stall, particularly at idle or when disengaging the clutch.

Most Likely Causes

1. Outdated Engine Control Module (ECM) Software 🔴 High Probability Subaru has officially recognized this issue by releasing Technical Service Bulletins (TSB #09-120-24 and the revised #09-120-24R) with updated software files to correct overly sensitive diagnostic logic for codes P0016, P0017, P0018, and P0019.
   How to confirm: Contact a Subaru dealership with your Vehicle Identification Number (VIN) to determine if the TSB is open and applicable to your car. A Reddit user with a 2018 Crosstrek confirmed a dealer fixed their P0019 with this update after recommending more expensive fixes first.
   Typical fix: A Subaru dealer or qualified shop must reprogram the ECM with the latest software version. This is typically a one-hour labor charge.
   Est. part cost: $0
2. Faulty Oil Control Valve (OCV) / VVT Solenoid 🟡 Medium Probability The OCV can become clogged with oil sludge or fail electronically, preventing it from properly regulating oil flow to the camshaft phaser. This is a common failure point on many modern engines with variable valve timing, including the FB20D. Subaru also issued a service bulletin regarding internal oil seals on the OCVs which could fail and cause oil to seep into the connector, leading to AVCS-related DTCs.
   How to confirm: A technician can test the solenoid's resistance with a multimeter (should be around 6.9-7.9 Ohms) or by applying 12V to see if it actuates. A common DIY method is to swap the suspect OCV (Bank 2, exhaust/lower position) with an identical one from another position (e.g., the intake OCV on the same bank) and see if the code changes (e.g., to P0018). If the code moves, the OCV is bad.
   Typical fix: Replace the Bank 2 exhaust oil control valve. It is located on the front of the driver's side cylinder head, typically the lower of the two solenoids.
   Est. part cost: $70-$150
3. Low or Dirty Engine Oil 🟡 Medium Probability Subaru's AVCS system is hydraulic and extremely sensitive to oil level, viscosity, and cleanliness. Incorrect or degraded oil can't maintain the pressure needed to adjust cam timing correctly. The FB20D engine, in particular, does not tolerate extended oil change intervals well.
   How to confirm: Check the oil dipstick for level and examine the oil's condition. If it is low, appears thick, sludgy, or is long past its change interval, this is a likely cause. Ensure the correct 0W-20 synthetic oil is being used.
   Typical fix: Perform an oil and filter change using the manufacturer-specified oil and a quality filter. Clear the code and drive to see if it returns. This is the cheapest and easiest first step after checking the TSB.
   Est. part cost: $40-$80
4. Failing Camshaft Position Sensor ⚪ Low Probability
   How to confirm: After ruling out software, oil, and the OCV, the sensor itself can be tested. The easiest way to confirm is to swap it with the corresponding sensor from Bank 1 (passenger side) to see if the code follows (changing to P0017). A Reddit user with a Crosstrek tried this, and when the code did not move, it correctly ruled out the sensor as the issue.
   Typical fix: Replace the Bank 2 exhaust camshaft position sensor.
   Est. part cost: $80-$110

Rare But Worth Checking

• Stretched Timing Chain or Timing Issue: While uncommon on a relatively new vehicle, a stretched timing chain or a failing chain tensioner can cause this code. This is a much more serious mechanical issue that typically involves significant labor. The FB20D uses two timing chains.
• Damaged Camshaft Phaser/Actuator: The actuator itself, which is mechanically responsible for shifting the cam timing, can fail. This is rare but possible, especially if the engine has been run with low or dirty oil for an extended period, leading to sludge and blockages.

Diagnosis Steps

1. Check for Technical Service Bulletins (TSBs): Before any other step, call a Subaru dealer with your VIN and ask if TSB #09-120-24R is open for your vehicle. If so, this is the most likely fix and should be the first action.
2. Check Engine Oil: Verify the engine oil level is full and the oil is clean and of the correct 0W-20 viscosity. If it's low or dirty, perform an oil and filter change, clear the code, and re-test.
3. Inspect & Swap the Oil Control Valve (OCV): Locate the OCV for the Bank 2 exhaust camshaft (driver's side, lower position). Inspect its wiring. Swap it with the intake OCV (upper position) on the same bank. Clear the codes and drive. If the code changes to P0018, the OCV you moved is faulty and needs replacement.
4. Inspect & Swap the Camshaft Position Sensor: Locate the camshaft position sensor for the Bank 2 exhaust. Check its wiring. Swap it with the identical sensor from Bank 1 (passenger side) to see if the code changes to P0017. If it does, the sensor is bad.
5. Professional Diagnosis: If the above steps do not resolve the issue, the problem may be more complex, such as a timing chain, phaser issue, or internal ECM fault, and requires professional diagnosis with advanced tools.

Parts You'll Likely Need

• Oil Control Valve (VVT Solenoid) (OEM #10921AA231) — This part is a common failure point that directly causes timing correlation codes by getting stuck or failing electronically. Both intake and exhaust OCVs use the same part number.
  Trusted brands: Subaru Genuine, Denso (often the OEM supplier), Hitachi
  OEM price range: $110-$150
  Aftermarket price range: $70-$120
• Camshaft Position Sensor (OEM #22056AA140) — Though less common than the OCV, a failing sensor can send incorrect data to the ECM, triggering this code. It's more often misdiagnosed than actually faulty.
  Trusted brands: Subaru Genuine, NGK/NTK, Denso
  OEM price range: $80-$110
  Aftermarket price range: $50-$90

Related Codes That Often Appear With This One

• P0018 — This code is for 'Crankshaft Position - Camshaft Position Correlation Bank 2 Sensor A (Intake)'. Seeing both P0018 and P0019 together strongly points to a systemic issue on the driver's side (Bank 2), such as an oil supply problem, a clogged OCV filter screen, or a timing chain issue affecting that entire bank.
• P0016 — This is the equivalent code for the intake camshaft on Bank 1. If seen with P0019, it could indicate a more widespread issue but is less common than seeing it with P0018. All four correlation codes (P0016-P0019) are addressed by the same TSB.
• P0017 — This is the equivalent code for the exhaust camshaft on Bank 1 (passenger side). Seeing both P0017 and P0019 simultaneously is rare but would suggest a major problem affecting the entire engine's timing, like a severely stretched timing chain or widespread oil contamination.

Technical Service Bulletins (TSBs) & Recalls

• 09-120-24R: Announcing availability of new reprogramming files for the Engine Control Module (ECM) to remedy DTCs P0016, P0017, P0018, and P0019. The bulletin states the files contain 'enhanced logic for the self-diagnosis program of the ECM'. This TSB applies to the 2017-22 Impreza and 2018-22 Crosstrek, among others.
• 09-120-24: Original bulletin announcing the ECM reprogram for the same set of DTCs. It has since been superseded by the 'R' version.
• 02-170-17R: Announces a redesigned AVCS oil control valve with an improved internal oil seal to prevent oil from seeping into the electrical connector, which can cause various AVCS-related DTCs.

Platform-Specific Known Issues

• The primary vehicle-specific issue is the need for an ECM software update as documented in Subaru TSBs #09-120-24 and #09-120-24R. The original software logic was too sensitive and could falsely trigger P0019 and related codes. This issue is shared with the Subaru Crosstrek, which uses the same FB20D engine.

Mechanic-Grade Diagnostic Values

• Engine Oil Pressure — expected: >10 PSI at warm idle; >30 PSI at 3000 RPM (warm engine). Failure: Pressure below these specifications indicates a mechanical oiling system problem that must be fixed before diagnosing AVCS components.
• VVT Advance Angle Amount (VVT Adv. Ang. Amount) via Subaru Select Monitor — expected: 0 degrees at idle (with OCV disconnected for test). Failure: A value more than ±10 degrees from 0 indicates a base timing issue (e.g., jumped timing chain).
• Oil Control Valve (OCV) / VVT Solenoid Resistance — expected: Approximately 6.9 - 7.9 Ohms. Failure: A reading outside this range indicates a faulty solenoid coil.

Scan Tool Commands That Help

• Subaru Select Monitor (SSM) or equivalent: Active Test / Actuator Test for Oil Control Valve — To directly command the OCV solenoid to actuate while the engine is running. A functional solenoid will cause the engine to hesitate or stall, confirming the solenoid itself is working.
• Subaru Select Monitor (SSM) or equivalent: Live Data Monitoring: 'AVCS Exhaust Left' and 'AVCS Exhaust Right' — To compare the commanded vs. actual cam angle for the affected bank (Bank 2, Left) against the healthy bank (Bank 1, Right). The values should react similarly during a drive cycle; if Bank 2's angle lags or is erratic, it points to a hydraulic or mechanical issue on that side.
• Subaru Select Monitor (SSM) or equivalent: Clear Memory / Cam/Crank Relearn — After replacing a component like an OCV or sensor, the ECM's learned values for AVCS may need to be reset. Some advanced aftermarket tools may also have this function, sometimes called a 'Test Mode Clear'.

Wiring & Ground Locations

• Bank 2 Exhaust Oil Control Valve Connector — On the front of the driver's side (Bank 2) cylinder head. It is the lower of the two OCV connectors on that side.. This is the direct electrical connection to the solenoid that controls the exhaust cam timing for Bank 2. Check for oil contamination (per TSB 02-170-17R), corrosion, or damage to the connector or wiring harness.
• Bank 2 Exhaust Camshaft Position Sensor Connector — On the driver's side (Bank 2) cylinder head, typically the lower of the two cam sensors. The connector is often designated E36 in wiring diagrams.. This sensor provides the feedback to the ECM on the exhaust cam's position. A poor connection here will cause a correlation code.

Real Owner Repair Stories

• Reddit user R2CEE2 in r/AskMechanics (2018 Subaru Crosstrek (shares FB20D engine and TSBs with Impreza)) — P0019 code
  ❌ Tried (didn't work) Replaced the bottom VVT solenoid (Bank 2 Exhaust OCV)., Swapped camshaft position sensors to see if the code would move to another bank.
  ✅ What actually fixed it The user replaced *both* VVT solenoids on Bank 2 and then performed a 'test mode clear' with a Thinkdiag2 scan tool, which resolved the code. Another user in the same thread reported that a dealer ECM update fixed their P0019 without replacing any parts.

OEM Part Supersession History

• 10921AA220 → 10921AA230, then 10921AA231 — The latest part, 10921AA231, incorporates a redesigned internal oil seal to prevent oil from seeping into the electrical connector, a known issue that can cause AVCS-related DTCs as per TSB 02-170-17R.
  Heads up: Older part numbers will physically fit but lack the improved seal design, making them more prone to failure over time. It is critical to use the latest revision (10921AA231) for replacement.