P0011

00:00What this code means

Code P0011. "A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1).

In plain English: the intake camshaft on bank one is staying farther advanced than the engine computer commanded, usually because the variable-valve-timing oil circuit cannot move it back correctly.

A short, gentle trip may be possible if the oil level and oil-pressure warning are normal and the engine is quiet. Stop if you hear timing-chain rattle, the engine stalls repeatedly, or the oil-pressure light comes on; continuing can turn a control problem into major engine damage.

00:37How the test actually works

Here's what your engine computer is actually measuring.

The engine computer commands an oil-control valve to route pressurized engine oil into a cam phaser. That phaser rotates the intake camshaft relative to the crankshaft. Cam and crank sensors let the computer compare the requested angle with the angle the camshaft actually reaches.

The code sets when actual cam angle remains more advanced than the commanded target for the calibrated amount of time. The exact angle, oil-temperature conditions and timer are vehicle-specific, so use factory data rather than treating one universal number as the limit.

So the code is not a part failure report. It's a performance measurement that came back under spec.

01:24Symptoms

What you'll usually notice, beyond the light itself.

Rough idle or stalling. Too much cam advance at idle reduces combustion stability, especially after the oil warms up.

Hard starting. A phaser parked in the wrong position can reduce effective compression during cranking.

Flat low-RPM response. Valve timing that helps at one speed can hurt cylinder filling badly at another.

Poor fuel economy and higher emissions. The computer is trying to run the engine around valve timing it cannot control accurately.

Timing-chain or cam-phaser rattle. Mechanical noise raises the urgency because it can mean oil-pressure, phaser or timing-chain wear rather than a simple electrical fault.

02:15Most likely causes, ranked

Now the part you came for: what actually causes this, ranked by how often it turns out to be the culprit.

32 percent of the time, it's this: Low, dirty or incorrect-viscosity engine oil. Variable valve timing is hydraulic. Check the dipstick and service history before testing or replacing any component.

25 percent of the time, it's this: Sticking bank 1 intake oil-control valve. Sludge or internal wear can leave the valve feeding the advance chamber after the computer commands it back.

15 percent of the time, it's this: Blocked oil-control screen or cam oil passage. Restricted flow makes actual cam timing slow or unable to return, even when the solenoid clicks electrically.

12 percent of the time, it's this: Worn or sticking camshaft phaser. A phaser can bind internally or fail to lock at rest, often with startup rattle.

10 percent of the time, it's this: Stretched timing chain or incorrect mechanical timing. Suspect this when base cam correlation is wrong, the engine rattles, or control tests on both cam directions fail.

6 percent of the time, it's this: Solenoid wiring, connector or control-software fault. Check power, control and connector condition; some applications also have manufacturer calibration bulletins.

Notice that the most expensive repair is not the most likely one. That matters, because the cheap checks come first.

03:50The measurement that decides it

This is the single measurement that tells you whether you need the expensive part or the cheap one.

With oil level and pressure verified, graph commanded and actual bank one intake-cam angle during the factory active test, or through a controlled RPM change if your scan tool cannot command the solenoid.

The commanded line steps from zero to twenty degrees and back. A healthy actual-angle trace follows it with a short, smooth delay and then returns close to zero.

The failed trace advances when asked but stays near twenty degrees after the command returns to zero. That is the over-advanced condition the computer is reporting.

If actual angle stays advanced, check oil condition, pressure, the control valve and its screen before opening the timing cover. If command itself is wrong, test the circuit and software path instead.

04:44Diagnostic order

So here is the order to actually test this, cheapest and most likely first.

Step 1. Is the oil full, clean enough, and the factory-specified viscosity? Check level on the correct surface and review the oil specification and service interval. If it is low, badly sludged or the wrong viscosity, correct that first, clear the code and repeat the monitor.

Step 2. Are oil pressure and base mechanical timing normal? An oil warning, startup rattle, correlation codes or low measured pressure moves this away from a simple solenoid diagnosis. Verify pressure with the factory procedure before commanding the phaser repeatedly.

Step 3. Does actual cam angle follow the commanded angle and return? Run the manufacturer active test while graphing both parameters. A trace that moves out but will not return confirms the performance fault; no movement at all can be electrical, hydraulic or mechanical.

Step 4. Does the oil-control valve pass its circuit and mechanical tests? Check the connector and control signal, then remove the valve only by the factory procedure. Inspect its screen and passages. A click alone does not prove that the spool moves freely or flows oil.

Step 5. Does the phaser move freely and is chain timing still correct? If oil supply and control are proven, inspect the cam phaser, chain stretch, guides and base timing. Use the locking and timing procedure for this exact engine.

That order separates an oil-service problem from a solenoid, phaser or timing-chain problem before the timing cover comes off.

06:33Repair costs

What this costs to put right, in US dollars, parts and labor.

Correct oil and filter service: 30 to 90 dollars in parts, plus about 0.5 hours of labor. Use the exact viscosity and specification listed for the engine.

Clean oil-control screen or passage: 5 to 40 dollars in parts, plus about 1.0 hours of labor. Access varies widely, and severe sludge needs a broader engine evaluation.

Camshaft oil-control valve: 40 to 250 dollars in parts, plus about 0.7 hours of labor. Test the circuit and inspect the oil path before replacing it.

Camshaft phaser: 150 to 600 dollars in parts, plus about 5.0 hours of labor. Often requires timing-chain disassembly even when the chain is reused.

Timing chain, guides and related hardware: 300 to 1200 dollars in parts, plus about 8.0 hours of labor. The high-cost branch, justified only after oil supply and control are proven.

P0011 can be a routine oil service or a major timing repair. Command-versus-actual data plus oil and solenoid checks are what keep those two outcomes from being confused.

07:54Recap and related codes

Quick recap. P0011 means the bank one intake cam stayed more advanced than commanded. Verify oil level, condition, specification and pressure; compare commanded with actual angle; test the oil-control valve and screen; then inspect the phaser and chain only if those checks pass.

If your scan tool showed a related code alongside this one, check those too: P0010, P0012, P0021, P0340.

Codes are on screen and linked below.