P0028 is an OBD-II trouble code that points to a problem with the variable valve timing (VVT) system on Bank 2 of your engine. In simple terms, your engine computer is not happy with how the intake cam on one side of the engine is responding when it commands more lift or advance. You might notice rough running, poor fuel economy, or a check engine light with no obvious drivability issue. Ignoring it can lead to bigger problems, so it’s worth understanding what it means and how to fix it.
What Does P0028 Mean?
P0028 stands for “Intake Valve Control Solenoid Circuit Range/Performance (Bank 2)” or “Intake Valve Control Solenoid – High (Bank 2),” depending on the manufacturer. It indicates that the engine control unit (ECU) commanded the Bank 2 intake cam to move to a higher lift or more advanced position, but the actual movement did not match what was expected.
This code is most often tied to the variable valve timing (VVT) or variable valve lift system. It can be caused by electrical issues, a sticking VVT solenoid, oil flow problems, or internal engine wear that prevents the cam phaser from reacting correctly.
Quick Reference
- Code: P0028
- System: Variable valve timing / intake valve control
- Bank: Bank 2 (cylinders opposite Bank 1)
- Severity: Moderate to high if ignored
- Common causes: Low/dirty oil, faulty VVT solenoid, wiring issues, cam phaser problems
Real-World Example / Field Notes
In the shop, I see P0028 most often on higher-mileage V6 and flat-4 engines where oil changes have been stretched too far. A typical case: customer comes in with a check engine light, slight rough idle, and says the car “feels lazy” on acceleration. Scan tool shows P0028 on Bank 2, plus a bit of valve train noise on that side. After checking oil level and condition, I usually find thick, dirty oil and a partially clogged VVT solenoid screen. A proper oil service and a new intake VVT solenoid on Bank 2 often bring the engine right back to life.
Symptoms of P0028
- Check engine light on: The MIL comes on and P0028 stores as a current or pending code.
- Rough idle: You may feel a shaky idle, especially when the engine is warm.
- Loss of power: Acceleration can feel flat or sluggish, particularly at higher RPMs.
- Poor fuel economy: You might notice more frequent fuel stops due to inefficient valve timing.
- Hard starting: In some cases, hot or cold starts take longer or require extra cranking.
- Engine noise: Light ticking or rattling from the Bank 2 valve cover area under certain conditions.
- Intermittent drivability issues: Symptoms may come and go as the VVT system occasionally sticks.
Common Causes of P0028
Most Common Causes
- Low or dirty engine oil: VVT systems rely on clean oil pressure. Old, thick, or low oil can starve the Bank 2 intake cam phaser and solenoid, causing slow or no response.
- Faulty intake VVT solenoid (Bank 2): The solenoid that controls oil flow to the intake cam on Bank 2 can stick, clog, or fail electrically, leading to incorrect cam timing.
- Clogged VVT oil passages or screens: Sludge and varnish can block the tiny oil passages or the mesh screens in the VVT solenoid, restricting flow to the cam phaser.
- Incorrect or wrong-viscosity oil: Using oil that is too thick or not to spec can slow the response of the VVT system, especially in cold weather.
- Wiring or connector issues: Corroded, loose, or damaged wiring to the Bank 2 VVT solenoid can cause range/performance faults.
Less Common Causes
- Worn or sticking cam phaser (Bank 2): Internal wear or sticking in the cam phaser can prevent the cam from reaching the commanded position.
- Timing chain or belt problems: Stretched timing chains, worn guides, or incorrect timing belt installation can affect cam position feedback.
- Faulty camshaft position sensor (Bank 2): If the sensor on Bank 2 is sending incorrect data, the ECU may think the cam is not moving correctly.
- ECU software or internal fault: Rarely, outdated calibration or a failing ECU can misinterpret VVT signals and set P0028.
- Mechanical engine damage: Severe sludge, low-oil damage, or internal wear in the head can affect oil delivery to the VVT system.
Diagnosis: Step-by-Step Guide
To diagnose P0028 properly, you should have at least a basic OBD-II scan tool, a digital multimeter, and access to service information for your specific vehicle. A more advanced scanner that can read live data and Mode $06 results is ideal. Hand tools, a good light, and possibly an oil pressure gauge also help.
- Confirm the code and check for companions: Scan the vehicle for P0028 and any related codes (like cam position or oil pressure codes). Note freeze frame data to see when the fault occurred (RPM, load, temperature).
- Inspect oil level and condition: Check the dipstick with the engine off and level. Low oil or thick, dark, sludgy oil is a red flag. Correct the level and consider an immediate oil and filter change with the correct viscosity.
- Visual inspection of VVT solenoid (Bank 2): Locate the Bank 2 intake VVT solenoid (usually on the cylinder head). Inspect the connector and wiring for corrosion, oil intrusion, broken insulation, or loose pins.
- Electrical tests on the solenoid: With the key off, unplug the solenoid and check resistance with a multimeter. Compare to spec. If it’s open, shorted, or far out of range, the solenoid is likely bad.
- Command the solenoid with a scan tool: If your scanner supports bi-directional control, command the Bank 2 intake VVT solenoid on and off while monitoring camshaft position data. The cam angle should change smoothly; if not, suspect a sticking solenoid or phaser.
- Check for restricted screens or sludge: On many engines, you can remove the VVT solenoid and inspect the small oil screens. If they are clogged with debris, clean or replace the solenoid and consider flushing the engine.
- Verify oil pressure (if needed): If the engine is noisy or you suspect lubrication problems, check oil pressure with a mechanical gauge. Low pressure can prevent the VVT system from working correctly.
- Inspect timing components (if symptoms persist): If the solenoid and oil system check out, you may need to inspect the timing chain/belt, guides, and cam phaser on Bank 2 for wear or misalignment.
- Check Mode $06 and readiness data: Some scan tools let you view VVT performance tests under Mode $06. This can show if the cam is barely passing or consistently failing commanded movements.
- Clear codes and road test: After repairs or cleaning, clear the codes and perform a road test under similar conditions to the freeze frame. Re-scan to confirm P0028 does not return.
Pro tip: If you have both P0028 and a similar code for Bank 1 (like P0026), compare live data for both banks. Differences in cam response between banks can quickly point you toward a bad solenoid or mechanical issue on the affected side.
Possible Fixes & Repair Costs
Repairs for P0028 range from simple maintenance to more involved engine work. In many cases, a proper oil and filter change with the correct viscosity, plus cleaning or replacing the Bank 2 intake VVT solenoid, solves the problem. If wiring is damaged, you may need connector repair or harness work. More serious cases involve replacing the cam phaser or timing components on Bank 2, which is labor-intensive.
Typical repair costs vary widely: an oil service might be $60–$150, a new VVT solenoid installed usually runs $150–$400, wiring repairs can be $100–$300, and cam phaser or timing chain work can range from $700 up to $2,000+ depending on the engine design and labor rates in your area. Clean maintenance history and easy access to components usually keep costs down, while severe sludge or internal wear pushes costs higher.
Can I Still Drive With P0028?
You can often still drive with P0028 for a short period, but it’s not something you should ignore. If the engine runs relatively smooth and there are no severe noises, you may be able to drive to a shop or finish short local trips. However, continued driving with a malfunctioning VVT system can increase fuel consumption, reduce performance, and accelerate wear on timing components. If you notice loud ticking, rattling, or a major loss of power, park the vehicle and have it towed to avoid possible engine damage.
What Happens If You Ignore P0028?
Ignoring P0028 can turn a relatively simple fix into a costly repair. A VVT system that does not respond correctly can cause long-term timing issues, extra stress on chains or belts, and uneven wear on cam and valve components. If low oil or sludge is the root cause, you risk damaging bearings and cam journals, which can lead to engine failure. Addressing the code early almost always saves money and protects engine life.
Related Codes
- P0027 – Exhaust Valve Control Solenoid Circuit Range/Performance Bank 1
- P0026 – Intake Valve Control Solenoid Circuit Range/Performance Bank 1
- P0019 – Crankshaft Position Camshaft Position Correlation Bank 2 Sensor B
- P0018 – Crankshaft Position Camshaft Position Correlation Bank 2 Sensor A
- P0017 – Crankshaft Position Camshaft Position Correlation Bank 1 Sensor B
- P0016 – Crankshaft Position Camshaft Position Correlation Bank 1 Sensor A
- P0009 – Engine Position System Performance Bank 2
- P0008 – Engine Position System Performance Bank 1
- P0007 – Fuel Shutoff Valve “A” Control Circuit High
- P0006 – Fuel Shutoff Valve “A” Control Circuit Low
Key Takeaways
- P0028 points to a problem with the Bank 2 intake valve control / VVT system, usually a range or performance issue.
- Low or dirty oil and a failing VVT solenoid are the most common causes, especially on higher-mileage engines.
- Symptoms can include a check engine light, rough idle, loss of power, and poor fuel economy.
- Early diagnosis with a scan tool, oil inspection, and basic electrical checks can prevent expensive engine damage.
- Repairs can be as simple as an oil change and solenoid replacement, but severe cases may require timing or cam phaser work.
Vehicles Commonly Affected by P0028
P0028 shows up most frequently on engines with advanced variable valve timing and multi-bank layouts. You’ll often see it on Subaru flat-4 and flat-6 engines, Honda and Acura V6 models with VTEC/VTC systems, Nissan and Infiniti VQ-series V6 engines, and various Toyota and Lexus V6/V8 engines with VVT-i. It’s also seen on some GM and Ford V6/V8 engines that use cam phasers on both banks. Any vehicle that has a Bank 2 intake VVT solenoid and relies heavily on oil quality is a candidate for this code, especially if oil changes have been neglected.
FAQ
Can P0028 go away on its own?
Sometimes P0028 will clear temporarily if conditions change, but the underlying issue usually remains. If it was triggered by borderline oil quality or a sticking solenoid, it may not set every drive cycle. However, once the ECU has seen the fault, it’s best to inspect the oil, check the VVT solenoid, and address the cause rather than hoping it disappears.
Is P0028 serious enough to damage my engine?
It can be if ignored. The code itself is a warning that the VVT system on Bank 2 is not responding correctly. If the cause is low oil, sludge, or a stuck phaser, continuing to drive can accelerate wear on timing components and bearings. Taking care of it early usually prevents major damage.
How do I know which side is Bank 2 on my engine?
Bank 2 is the side of the engine that does not contain cylinder 1. The exact location depends on the engine layout and manufacturer. Service information or an under-hood label often shows cylinder numbering. If you’re unsure, a repair manual or a professional technician can help you identify Bank 2 before replacing any parts.
Can a simple oil change fix P0028?
In many cases, yes, especially if the oil was very low or overdue. Fresh oil of the correct viscosity can restore proper VVT operation if the solenoid and phaser are still healthy. However, if the solenoid is already damaged or the screens are clogged with sludge, you may still need to replace the Bank 2 intake VVT solenoid.
Do I need to replace both VVT solenoids if only P0028 is set?
Not always. If only Bank 2 is failing and Bank 1 is working normally, you can usually replace just the Bank 2 solenoid after proper diagnosis. On high-mileage engines, some owners choose to replace both banks as preventative maintenance, but it’s not mandatory if Bank 1 tests good and there are no related codes.