What does a P0011 code mean?

It means the camshaft the control unit calls A on bank one, which on nearly all engines is the intake camshaft, is phased further advanced than the unit commanded. Variable valve timing rotates the camshaft using oil pressure, and the unit compares the angle it asked for against the angle it measures from the camshaft and crankshaft sensors. When the measured angle stays too far advanced for too long, this code is stored.

Can an oil change fix a P0011 code?

Often, yes, and it is the correct first step rather than a delaying tactic. The phaser that moves the camshaft is a hydraulic device driven by engine oil, controlled through a solenoid valve with a fine gauze screen on it. Dirty oil, oil of the wrong viscosity, or a screen clogged with debris all stop the phaser responding properly. Use the exact specification the manufacturer lists, not simply a good oil, and have the control valve screen cleaned at the same time.

Is it safe to drive with a P0011 code?

For short journeys, yes, though the engine will be down on power and economy. Two things should change that answer: a rattle from the timing drive for the first second or two after a cold start, which suggests the chain rather than the oil control valve, and a low oil level or oil pressure warning, which means the phaser is not the only part being starved. Either of those means a garage rather than a commute.

Will P0011 fail an MOT?

Yes. An illuminated engine management lamp is a major defect on petrol cars first used on or after 1 July 2003 and diesels from 1 July 2008, and that defect accounts for 371,859 failures in the DVSA data behind this site. Cam timing faults are also one of the code families most likely to fail the gas readings independently, because valve timing directly changes the hydrocarbon and lambda figures the fast idle test measures.

Powertrain code · standard

P0011Camshaft timing stuck too far advanced, bank 1

Standard definition: "A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)

Last updated 27 July 2026

Quick answer

The variable valve timing on bank one's first camshaft, normally the intake camshaft, is sitting more advanced than the control unit asked for, or is not moving to where it was told to go. On the great majority of cars this is an oil problem before it is a mechanical one.

How the car works this out

Variable valve timing works by rotating a camshaft slightly relative to the chain or belt driving it, using engine oil pressure directed by an electrically operated control valve. The control unit knows exactly what angle it commanded, and it can measure the angle actually achieved by comparing the camshaft sensor signal against the crankshaft sensor signal. If the measured position stays advanced of the commanded one by more than a set tolerance, for longer than a set time, the code is stored. Because the entire mechanism is driven by oil, this is far more often a symptom of dirty, thin or insufficient oil than of a broken part — which is why the first step is a service item rather than a component.

What you might notice

A rough or hunting idle, sometimes bad enough to stall
Hesitation and a flat spot low down, with the engine feeling like it has lost its bottom end
Poorer fuel consumption
A rattle for a second or two after a cold start on some engines
The engine management lamp on, occasionally with reduced power

What causes it

Most likely first. A code names the check that failed, not the part that failed it, so more than one of these can produce the same number.

1Engine oil that is dirty, overdue or of the wrong viscosity, comfortably the most common cause and the cheapest to rule outCommon
How to check: Look at the service history and at the oil on the dipstick. If it is black and thin and the change is overdue, do that first with the exact grade the manufacturer specifies. A great many of these codes never come back afterwards.
2A blocked filter screen on the oil control valve, which catches debris before it reaches the phaserCommon
How to check: The valve usually comes out with one fastener and carries a fine gauze screen. It is often visibly clogged, and cleaning it is a job with almost no parts cost.
3A sticking or failed oil control valve, also called the camshaft actuator solenoid or VVT solenoidCommon
How to check: It can be commanded on and off with a diagnostic tool while watching the cam angle respond on live data, or removed and bench tested with a battery to see whether the spool moves freely and returns.
4Sludge in the oil galleries feeding the phaser, on an engine with a history of missed servicesPossible
5A worn camshaft phaser that can no longer hold the position it is set toPossible
How to check: A rattle for the first second or two after a cold start, from the phaser's locking pin failing to hold, is the usual accompaniment.
6Low oil level, or a worn oil pump that cannot maintain pressure at idlePossible
How to check: Check the level cold on level ground. If the level is fine, an oil pressure gauge fitted in place of the pressure switch will settle whether the pump is keeping up.
7Damaged wiring or a corroded connector at the control valvePossible
8A stretched timing chain, which shifts the base timing the phaser works fromLess common
How to check: Look for a correlation code such as P0016 stored alongside, and listen for chain rattle at start-up.

What to do about it

1Change the oil and filter with the exact grade the manufacturer specifies, before anything else. This is not being fobbed off: the phaser is a hydraulic device and it can only work with clean oil at the right viscosity, and using a thicker oil than specified is enough on its own to cause this.
2Have the oil control valve removed and its screen cleaned while the oil is out. It is a few minutes of extra work at that point and a much bigger job later.
3If the code returns, have the valve tested properly by commanding it on the diagnostic tool and watching whether the camshaft angle follows.
4Only then start looking at the phaser and the chain. Those are workshop jobs and there is no sense reaching them before the cheap causes have been eliminated.
5Check for other codes stored at the same time. A correlation code such as P0016 alongside this one changes the priority completely and moves the chain to the top of the list.

Can you keep driving?

Briefly, gently

The engine runs, but it is running with its valve timing in the wrong place, which costs power and economy and does the emissions no good. It is not an emergency unless there is a rattle from the timing drive, which suggests the chain rather than the oil valve. Get the oil changed promptly, because if low oil pressure is behind it then the phaser is not the only part suffering.

Will it fail an MOT?

Valve timing sits directly on top of the emissions readings, which makes this a more genuine emissions fault than most codes that light the lamp. Get the cam timing wrong and the amount of burnt gas left in the cylinder changes, which moves the hydrocarbon reading and pushes the lambda value away from the narrow band around 1.00 that the fast idle test requires. So the car can fail on the gas readings as well as on the lamp, and the lamp alone is a major defect on petrol cars first used from 1 July 2003 and diesels from 1 July 2008.

The light this turns on

Engine management lightThe engine management system has found a fault it cannot correct and has stored a code for it. The car will usually still drive, but an illuminated engine light is an automatic MOT failure on petrol cars first used from 1 July 2003 and diesels from 1 July 2008.

Common questions

What does a P0011 code mean?: It means the camshaft the control unit calls A on bank one, which on nearly all engines is the intake camshaft, is phased further advanced than the unit commanded. Variable valve timing rotates the camshaft using oil pressure, and the unit compares the angle it asked for against the angle it measures from the camshaft and crankshaft sensors. When the measured angle stays too far advanced for too long, this code is stored.
Can an oil change fix a P0011 code?: Often, yes, and it is the correct first step rather than a delaying tactic. The phaser that moves the camshaft is a hydraulic device driven by engine oil, controlled through a solenoid valve with a fine gauze screen on it. Dirty oil, oil of the wrong viscosity, or a screen clogged with debris all stop the phaser responding properly. Use the exact specification the manufacturer lists, not simply a good oil, and have the control valve screen cleaned at the same time.
Is it safe to drive with a P0011 code?: For short journeys, yes, though the engine will be down on power and economy. Two things should change that answer: a rattle from the timing drive for the first second or two after a cold start, which suggests the chain rather than the oil control valve, and a low oil level or oil pressure warning, which means the phaser is not the only part being starved. Either of those means a garage rather than a commute.
Will P0011 fail an MOT?: Yes. An illuminated engine management lamp is a major defect on petrol cars first used on or after 1 July 2003 and diesels from 1 July 2008, and that defect accounts for 371,859 failures in the DVSA data behind this site. Cam timing faults are also one of the code families most likely to fail the gas readings independently, because valve timing directly changes the hydrocarbon and lambda figures the fast idle test measures.

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