General

P0016Crankshaft and camshaft position correlation, bank 1 sensor A

Crankshaft Position - Camshaft Position Correlation Bank 1 Sensor A

Get it diagnosed soon

Generic OBD-II code

Camshaft Position (CMP) Sensor

What this part does

Reports camshaft position/rotation so the control module can time fuel injection, ignition, and variable valve timing correctly.

What the computer is measuring

The crankshaft and the camshaft are mechanically linked, normally by a chain or a belt, and they turn in a fixed relationship: the camshaft at half crankshaft speed. Both have position sensors, and the computer reads them constantly. It needs the crankshaft signal to know when to fire, and the camshaft signal to know which stroke each cylinder is on.

Because the two are mechanically tied, the computer knows exactly where the camshaft signal should fall relative to the crankshaft signal. It checks that continuously. P0016 means the camshaft signal is arriving outside the window where it belongs.

There are only really two ways that happens. Either the mechanical relationship has genuinely changed, or one of the two signals is wrong.

The mechanical case is the one that matters. A timing chain stretches as it wears, and a stretched chain lets the camshaft lag behind the crankshaft. Left long enough, chains jump teeth, and on an interference engine that means valves and pistons meeting. A rattle from the timing cover on start up alongside this code should be treated as urgent rather than as a noise to keep an eye on.

The signal case covers a failed sensor, a damaged reluctor ring, chafed wiring, or a variable valve timing phaser drifting because the oil driving it is low or dirty. Those are all cheaper outcomes, and they are worth ruling out properly, but do the ruling out promptly rather than driving on the code for months.

What you will notice

  • Steady check engine light.
  • Long cranking before the engine starts, or a no start.
  • Rough running and misfires once it does start.
  • A rattle from the timing cover, worst on start up.
  • Noticeable loss of power.

Likely causes, most common first

Ordered by how often each one actually turns out to be the problem, not alphabetically and not by part price.

  1. A stretched timing chain or worn chain guides

    The most serious and one of the most common causes. As the chain stretches, the camshaft falls behind the crankshaft and the relationship the computer checks drifts out of tolerance.

  2. A camshaft phaser stuck or failing to hold position

    On an engine with variable valve timing the phaser can drift or lock, which changes the correlation the computer measures.

  3. Low or contaminated engine oil

    The phaser is oil driven. Low pressure or sludged oil lets it wander, and that shows up as a correlation fault.

  4. A failed camshaft or crankshaft position sensor

    The computer is comparing two sensor signals. A bad reluctor ring, a damaged sensor or a chafed wire corrupts the comparison with the mechanical timing intact.

  5. Timing components fitted incorrectly after previous work

    A chain or belt off by one tooth produces this code immediately. If the engine has had recent timing work, start here.

What to check, in order

  1. Check the oil level and condition, and confirm the correct grade is in it.

    Low or degraded oil can cause this on its own and makes every other test unreliable. Correct it first.

  2. Ask what work the engine has had recently.

    A code that appeared straight after a timing chain, belt or phaser job points at assembly rather than wear, and rechecking the marks is far cheaper than any further diagnosis.

  3. Inspect both position sensors and their wiring, and check the reluctor rings for damage or debris.

    A damaged sensor or a metal shaving on a reluctor explains a correlation error with correct mechanical timing.

  4. Listen for chain rattle on a cold start and check the chain tensioner and guides.

    Audible rattle and a tensioner extended near its limit confirms chain stretch, which is a mechanical repair.

  5. Verify the timing marks physically if the tests above have not explained it.

    This is the definitive answer. Marks that line up rule out mechanical timing entirely and leave the sensors and the phaser.

Where this one turns up most

  • Engines known for timing chain stretch, particularly where long oil change intervals have been used.
  • Any engine that has had recent timing chain or belt work.

Codes that often show up alongside it

What a DriveDecode adapter can read

A DriveDecode adapter reads engine and emissions systems: the powertrain and emissions codes the OBD-II standard requires on every US vehicle it covers. It does not read ABS, airbag (SRS), TPMS or transmission-specific manufacturer codes. Those need make-specific decoding that generic OBD-II hardware cannot do.

Reading P0016 on your own car

DriveDecode pulls P0016 straight off the vehicle along with the freeze frame the computer stored when it set: the coolant temperature, engine load and speed at that exact moment. That context is what separates a fault that happens on a cold start from one that happens under load, and it is the first thing the list above asks you to narrow down.

See how DriveDecode works

Last reviewed 2026-09-05. Definition sourced from the published standard.