P0021: Intake Camshaft Timing Over-Advanced (Bank 2)
Key takeaways
- P0021 means the variable valve timing system moved the bank 2 intake camshaft further than the computer asked for, or couldn't hold it on target.
- It only sets on engines with two cylinder banks, such as V6, V8 and flat (boxer) engines.
- Low oil, the wrong viscosity or old sludgy oil is the first thing to rule out, because the timing system is moved by oil pressure.
- The usual part is the oil control (VVT) solenoid at $150–$450; a cam phaser or timing chain job is the expensive end at $800–$3,000.
- Subaru has engine computer reprogramming for P0021 on 2023 models, and Ford bulletins blame debris sticking the solenoid, so ask for a bulletin check first.
What P0021 means
The part of your engine that shifts intake cam timing on bank 2 went further than the computer told it to, or couldn’t hold where it was told. Scanners call it “A Camshaft Position Timing Over-Advanced or System Performance (Bank 2).” “A” is the intake cam on most engines, and bank 2 is the side without cylinder 1, so this code only appears on V6, V8 and flat engines. The engine computer sends oil to a cam phaser through an oil control solenoid, then compares the actual cam angle from the cam sensor with the angle it commanded. When the gap stays too large, it sets P0021. It is the bank 2 twin of P0011.
Is it safe to drive?
Short trips, yes, while you check the oil. The car may idle rough, hesitate or use more fuel, and some cars go into a reduced-power mode.
The symptoms that change the answer: a rattle from the engine for a few seconds at startup, stalling, an oil pressure light, or a flashing check engine light. Those point to low oil pressure, a worn phaser or a stretched timing chain, and driving on them can turn a solenoid job into an engine job. Park it and get it checked. If it has already stalled on you, car stalls while driving covers what to do.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Low oil, wrong viscosity or overdue oil | Check the dipstick and the service record; compare the grade used with the one on the oil cap | $50–$120 oil change |
| Engine software needing an update | Shop or dealer checks for an engine computer bulletin | $100–$200, or free under warranty |
| Bank 2 intake oil control (VVT) solenoid sticking or its screen clogged | Command it with a scan tool and watch the cam angle respond; pull it and look at the screen | $150–$450 |
| Wiring or connector at the solenoid | Check resistance and the plug for oil wicking into it | $100–$250 |
| Bank 2 intake cam phaser sticking or worn | Cam angle won’t follow commands with a good solenoid and good oil pressure; startup rattle | $800–$2,000 |
| Stretched timing chain or worn guides | Correlation code P0018 alongside; chain slack on inspection | $1,200–$3,000 |
What to check first
- Check the oil level and grade. Top up or change to the viscosity on your oil cap, clear the code and drive a few days. This fixes more over-advanced codes than you’d think.
- Read every stored code. P0021 with P0011 points to oil or software, which affect both banks. P0021 alone points to the bank 2 solenoid or phaser.
- Ask for a bulletin and software check. On many newer cars the fix is a computer update.
- Test the bank 2 oil control solenoid with a scan tool and inspect its screen for debris. On V engines, swapping the bank 1 and bank 2 solenoids and seeing whether the code moves to P0011 is a cheap test where the parts are the same.
- Look at the wiring to the solenoid for oil in the connector.
- Only then look at the phaser or chain, and ask for the cam/crank correlation data that justifies it.
Bulletins show two patterns. Subaru has engine computer reprogramming for “rare cases” of P0011 and P0021 on the 2023 Forester, Impreza and Crosstrek. Ford and Lincoln describe small debris making the variable cam timing solenoid stick on many 2015–2021 models, including the Edge, Fiesta, MKC and Aviator; separate Ford bulletins cover the 2019–2020 F-150 5.0L and the 2020–2021 Transit 3.5L.
What it costs
The cheap outcome is an oil change for $50–$120, or a software update. The common outcome is an oil control solenoid, $150–$450 installed. The expensive outcome is a cam phaser ($800–$2,000) or a timing chain job ($1,200–$3,000). Diagnosis first matters here, because a phaser or chain replaced on a car that only needed the right oil is money gone.
Related codes
P0021 often shows up with P0011, the same fault on bank 1, or P0022 (bank 2 intake retarded). P0024 is the bank 2 exhaust cam code; GM bulletins on some 2016–2019 Cadillac ATS and 2018 Traverse and Enclave list P0011, P0014, P0021 and P0024 setting together. 29 complaints filed with NHTSA mention P0021, led by the Subaru Impreza (5), Chevrolet Traverse (3) and Hyundai Santa Fe (3). Those are owner reports, not confirmed causes.
What owners report to NHTSA
29 complaints filed with NHTSA mention P0021, 24 of them since 2015, across 19 different models. The component owners most often filed it under: engine.
Most-reported models
| Vehicle | Complaints | Model years reported |
|---|---|---|
| SUBARU IMPREZA | 5 | 2006, 2007, 2012, 2013, 2014 |
| CHEVROLET TRAVERSE | 3 | 2018 |
| HYUNDAI SANTA FE | 3 | 2016, 2017 |
Manufacturer service bulletins that name P0021
68 technical service bulletins and manufacturer communications filed with NHTSA mention P0021, from 10 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- SUBARU FORESTER (2023), bulletin 10237260: This bulletin announces availability of reprogramming files for the Engine Control Module (ECM) to address rare cases of DTCs P0011 (A Camshaft Position Timing Over-Advanced or System Performance Bank 1) and P0021 (A Cam…
- SUBARU IMPREZA (2023), bulletin 10237264: This bulletin announces availability of reprogramming files for the Engine Control Module (ECM) to address rare cases of DTCs P0011 (A Camshaft Position Timing Over-Advanced or System Performance Bank 1) and P0021 (A Cam…
- SUBARU CROSSTREK (2023), bulletin 10237262: This bulletin announces availability of reprogramming files for the Engine Control Module (ECM) to address rare cases of DTCs P0011 (A Camshaft Position Timing Over-Advanced or System Performance Bank 1) and P0021 (A Cam…
- FORD EDGE (2015, 2016, 2017, 2018), bulletin 10194428: Some 2015-2021 Ford and Lincoln vehicles may exhibit an illuminated MIL with diagnostic trouble codes (DTC) P0011, P0012, P0014, P0015, P0016, P0017, P0018, P0019, P0021, P0022, P0024 and/or P0025. This may be due to sma…
- LINCOLN AVIATOR (2020, 2021, 2017, 2018), bulletin 10194428: Some 2015-2021 Ford and Lincoln vehicles may exhibit an illuminated MIL with diagnostic trouble codes (DTC) P0011, P0012, P0014, P0015, P0016, P0017, P0018, P0019, P0021, P0022, P0024 and/or P0025. This may be due to sma…
- FORD TRANSIT (2020, 2021), bulletin 10199525: Some 2020 Transit vehicles equipped with a 3.5L Duratec engine and all 2021 Transit vehicles built on or before 01-Jul-2021 may experience an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DT…
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
What is the difference between P0011 and P0021?
Both mean the intake cam is more advanced than commanded. P0011 is bank 1, the side with cylinder 1; P0021 is bank 2. Both at once point to something shared by the whole engine, such as oil or software, rather than a part on one side.
Can low oil cause P0021?
Yes, and it's the first thing to check. The variable valve timing system uses engine oil pressure to move the camshaft, so low oil, the wrong viscosity or dirty oil can make it overshoot. Top up or change to the grade on the oil cap or in the owner's manual, clear the code and see if it returns.
Can I drive with P0021?
For short trips, usually. The car may idle rough or feel down on power. If you hear a rattle at startup, it stalls, or the oil light flickers, park it, because low oil pressure or a stretched chain can damage the engine.
Will a new VVT solenoid fix P0021?
Often, if the oil is right and the solenoid sticks or its screen is clogged. A shop can command it with a scan tool and watch the cam angle respond before you buy one. On some Ford engines the bulletin fix starts with debris, not a new part.