P0026 Code: Intake Valve Control Solenoid Circuit Range/Performance B1
The oil-operated valve control on the bank 1 intake side isn't responding as commanded. Check the oil first.
Unverified: this manufacturer-specific definition comes from a single source or varies by model. Confirm it with a brand-specific scan tool.
At a glance
Severity: Low
- Meaning
- Intake Valve Control Solenoid Circuit Range/Performance B1
- System
- Fuel & Air Metering · Powertrain
- Safe to drive?
- Yes, short term
- Typical repair cost
- $0–$3,000
- DIY difficulty
- Easy
An intake valve control solenoid is an oil valve: the engine computer energizes it to route oil pressure into a mechanism that changes how the intake valves open. Depending on the manufacturer that means switching between two valve lift profiles, as on Subaru's AVLS, or shifting the intake camshaft timing. P0026 is a range/performance code, which means the solenoid's electrical circuit may be perfectly fine, but the result the computer checks – through the camshaft signal or an oil pressure switch, depending on design – doesn't match the command. What the solenoid actually controls varies by make, so check service information for your engine. Because the whole system runs on engine oil, low oil level, old or wrong-viscosity oil and a clogged screen at the solenoid are by far the most common causes.
Can I keep driving? Generally safe to drive while you sort out the oil. If the engine rattles, loses power noticeably or the oil pressure light comes on, stop and check the oil level right away.
Try this first – 5-minute fix
- Check the oil level Engine off, car level, wait a few minutes and read the dipstick. If it's low, top up with the grade in the owner's manual; a quart low is often enough to trigger P0026 on engines that burn a little oil.
- Change oil and filter if it's due or dirty Old, thickened oil can't flow through the small passages to the solenoid quickly enough. Fresh oil of the right viscosity, with a quality filter, fixes a large share of these codes.
- Clear the code and drive normally Clear P0026 and drive for a few days, including some highway driving. If it stays away, keep a closer eye on the oil level from now on.
How to read P0026
- P Powertrain
- 0 Generic (SAE)
- 0 Fuel/air & emissions (aux.)
- 26 Specific fault
Symptoms
- Check engine light, often shortly after the oil has run low or gone past its change interval
- Slightly rough idle or a flat spot at low or high rpm, depending on which lift or timing mode is stuck
- Reduced power or sluggish pull through the middle of the rev range
- Ticking from the top of the engine when the oil level is low
- Code returns within a few drives after clearing
Possible causes
Ranked by how often each cause is behind this code (editorial estimate).
- Low oil level, or oil that is old, sludged or the wrong viscosity
- Clogged oil screen or filter gasket at the solenoid
- Solenoid spool sticking from varnish or debris
- Low engine oil pressure from wear or a failing oil pump
- Valve lift mechanism or intake cam phaser sticking mechanically
- Intermittent wiring or connector at the solenoid
Diagnosis step by step
Match the code to your engine's system
Find out what the intake valve control solenoid operates on your engine: a two-step lift system or intake cam timing. Look at other codes too; P0010 to P0014 alongside point to the cam timing side, a low oil pressure code points to the oil supply itself.
Tools: OBD-II scanner
Measure the solenoid coil
Unplug the solenoid and measure its coil resistance; many read in the single-digit to low-teens ohm range, but use your engine's spec. An open or shorted coil would normally set a circuit code, so a normal reading confirms the problem is hydraulic or mechanical.
Tools: Multimeter
Command the solenoid with a scan tool
If your scan tool offers an output test, switch the solenoid on at warm idle. You should hear a click and see a change in idle quality or cam angle. A click with no engine response points to oil supply or the mechanism, not the solenoid's electrics.
Tools: OBD-II scanner
Remove and inspect the solenoid screen
Remove the solenoid (usually one or two bolts on the cylinder head or timing cover) and check its screen or gasket filter for sludge and debris. Clean it carefully or replace the gasket-filter, and check that the spool moves freely when you apply 12 volts briefly.
Tools: Screwdriver, Multimeter
Verify oil pressure if the code persists
If fresh oil and a clean solenoid don't cure it, have the oil pressure measured with a mechanical gauge at warm idle and at about 2,500 rpm. Pressure below spec explains why the valve control can't respond and needs fixing first.
Where the parts are
- 1Ignition coil
- 2Spark plug
- 3Fuel injector
- 4Camshaft sensor
- 5Crankshaft sensor
- 6Engine computer (ECM)
- 7Intake manifold
Repair options & costs
| Repair | DIY? | Estimated cost |
|---|---|---|
| Top up or change oil and filter | Yes | $0–$120 |
| Clean the solenoid screen or replace the gasket-filter | Yes | $10–$150 |
| Replace the intake valve control solenoid at a shop | No | $180–$450 |
| Diagnose and repair low oil pressure | No | $500–$3,000 |
Rough US estimates for parts and labor; shop rates vary by region. Not a quote.
Notes by brand
Subaru
On the 2.5-liter SOHC boxer with AVLS (active valve lift), used in the Forester, Impreza, Legacy and Outback, P0026 is a well-known code. Low oil level and a clogged oil switching solenoid filter are the usual causes, and topping up or changing the oil, then cleaning or replacing the solenoid and its gasket-filter, usually cures it.
Emissions / smog test impact
Will fail
P0026 turns on the check engine light, so a car with it stored fails an OBD-II smog check. After the fix, drive a few days so the monitors are ready before the test.
Frequently asked questions
Can low oil really set P0026?
Yes, it's the most common cause. The solenoid can only move the lift or timing mechanism if enough oil pressure reaches it. A low level, especially in hard cornering or braking, or thick old oil, slows the response enough for the computer to flag it.
Is P0026 the same as a VVT code?
Not exactly. On some engines the intake valve control solenoid is the cam timing solenoid, on others it switches valve lift, as on Subaru's AVLS. The fault logic is the same idea, but what you inspect depends on the engine.
The solenoid clicks when I test it. Is it still bad?
It can be. A click only proves the coil works. A spool that's sticky from varnish, or a clogged screen, can still stop oil from reaching the mechanism. Remove it and inspect before buying a new one.
What happens if I ignore P0026?
The engine usually keeps running, with a little less power in part of the rev range. The bigger risk is the cause: if it's low oil or low oil pressure, ignoring it can lead to real engine wear.
Sources
- SAE J2012 – Diagnostic Trouble Code Definitions
- ISO 15031-6 – Road vehicles, diagnostic trouble code definitions (EOBD)
- Manufacturer public service information (cross-checked)
- Methodology: How We Build Code Pages · Data Sources We Use · Editorial Policy