P0015
Powertrain"B" Camshaft Position - Timing Over-Retarded (Bank 1)
Most of the time this comes down to oil. Either the level has dropped, the oil's overdue and gummed up, or the wrong grade has gone in, and that starves the variable valve timing system of the clean pressure it needs. The technical side: the ECU is telling the exhaust camshaft phaser on bank 1 to advance, but the cam keeps sitting too far retarded compared to what was commanded, so the module flags P0015. It's a mechanical or hydraulic timing problem the engine can't correct on its own.
ⓘ Information only. This page provides general educational information about fault code P0015. We do not assess the urgency or safety implications of any specific fault. That requires in-person diagnosis by a qualified mechanic. Full terms.
Recommended next steps
Whether a fault is urgent, drivable, or routine depends entirely on the cause on a specific vehicle, and that can only be determined by a qualified mechanic with diagnostic equipment. If a warning light is illuminated, the most reliable next step is professional diagnosis.
What does P0015 mean?
P0015 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: "B" Camshaft Position - Timing Over-Retarded (Bank 1).
This is a standardised OBD-II code. The technical definition is the same regardless of the make or model of vehicle, although specific causes and symptoms can vary between vehicles.
Symptoms commonly associated with this code
Symptoms that drivers often report alongside this code. Not all may apply to every case:
- • Engine warning light on, often the first thing you notice
- • Lumpy or unsettled idle, worst when the engine's cold and the oil is still thick
- • Flat spot or hesitation when you put your foot down
- • Fuel economy creeping up without an obvious reason
- • Occasional misfire or stumble pulling under load
- • A rattle from the front of the engine on cold start if the timing chain or tensioner is involved
Possible causes
Causes commonly associated with P0015, listed in approximate order of typical investigation. The actual cause on a specific vehicle can only be confirmed by professional diagnosis.
- 1. Low, dirty, or wrong-viscosity oil. This is the first thing to rule out because the VVT system runs entirely on oil pressure, and a 0W-20 engine running on whatever was lying around in the garage will throw this all day
- 2. Sticking VVT solenoid (oil control valve) clogged with carbon and varnish, so it can't meter oil to the phaser properly
- 3. Worn camshaft phaser that no longer holds or adjusts its position under hydraulic pressure
- 4. Clogged oil galleries or a blocked screen feeding the solenoid, starving the phaser even when the oil itself is fine
- 5. Stretched timing chain or a tired tensioner letting the cam drift out of phase mechanically. Common on higher-mileage chain-driven engines
- 6. Faulty camshaft position sensor or a corroded connector reporting the cam's position wrongly
How mechanics typically diagnose
A typical diagnostic sequence used by mechanics, provided here for educational reference only. Diagnostic work should be performed by a qualified mechanic with the appropriate tools and training.
- 1. Check the oil level and condition before touching anything else. If it's low, black, sludgy, or the wrong grade, do an oil and filter change with the correct spec and clear the code. A good number of P0015s never come back after this
- 2. Pull all stored codes and read the freeze-frame data. A camshaft sensor code like P0340 or a chain code alongside this points you somewhere very different to a lone P0015
- 3. Inspect the wiring and plugs at the camshaft position sensor and the VVT solenoid for green corrosion, oil contamination, or chafing
- 4. Watch live data on a scan tool, comparing commanded cam angle against actual at idle and as the revs come up. A phaser that won't move when commanded tells you it's the solenoid, the phaser, or oil supply
- 5. Remove and bench-test the VVT solenoid. Check it clicks and isn't packed with sludge, and confirm its resistance is in spec
- 6. If the electrics and oil supply all check out, you're looking at mechanical timing. Inspect the chain stretch and tensioner, and verify the cam timing marks line up
Common questions about P0015
How long is this in the garage for? +
Depends entirely on what's behind it. An oil and filter change to clear a marginal P0015 is an hour, in and out. Swapping a VVT solenoid is usually half a day on most engines once you've got the inlet manifold or covers off to reach it. If it turns out to be the camshaft phaser or a stretched timing chain, you're looking at a full day or more, because the front of the engine has to come apart, and on transverse layouts that's a proper job. Get the cause confirmed before you book the work in so you're not paying for a chain job that a £40 oil service would have sorted.
Can I save money with a pattern VVT solenoid, or do I need the genuine part? +
For the solenoid, a decent quality aftermarket part from a known brand like Febi, Hella, or INA is fine and will save you a fair bit over main dealer prices. Steer clear of the no-name £15 specials off the auction sites though, because a solenoid that doesn't meter oil accurately will just set the code again and have you chasing your tail. For the camshaft phaser, I'd lean towards OEM or a top-tier aftermarket unit. It's not a part you want to be doing twice given the labour to fit it.
Is it alright to keep driving like this? +
Short term, on a light fault, the car will usually run with a rough idle and a bit less poke, and it won't strand you. But don't ignore it for weeks. If the cam timing is drifting because of a worn chain or a failing phaser, carrying on risks the timing slipping far enough to cause real mechanical damage, and on some engines a chain that lets go takes the valves with it. Sort it sooner rather than later, especially if you can hear a rattle on start-up.
Will this stop me passing the MOT? +
The P0015 code on its own won't fail you. What the tester looks at is whether the engine warning light is lit at the time of the test. If the MIL is on, that's an automatic fail on the emissions and warning lamp check regardless of which code is behind it. Fix the underlying problem, clear the light, and drive a few cycles to make sure it stays off before you take it in.
Information only, not professional advice
The information on this page is provided for general guidance and educational purposes only. It is not a substitute for diagnosis or repair advice from a qualified mechanic. Always verify any fault before paying for repairs. carfaultcodes.co.uk accepts no liability for decisions made based on this information. Full terms →