Crankshaft/Camshaft Position Correlation (Bank 1, Sensor A)
In short
P0016 means the camshaft and crankshaft are out of their expected timing relationship — the computer compares the two position sensors and they don't line up. The most common real-world causes are a stretched timing chain (and worn guides/tensioner), a stuck or failed VVT/cam phaser, or low/dirty oil starving the variable-valve-timing system. It's more serious than a simple sensor code and shouldn't be driven hard until diagnosed.
Is it safe to drive with P0016?
Limit driving until it's diagnosed. P0016 often points to timing-chain stretch or a VVT phaser problem; if a chain jumps a tooth, an interference engine can suffer serious valve/piston damage. The car may run rough or enter limp mode. Check oil level immediately and avoid hard acceleration until you know whether it's a sensor, oil, or mechanical cause.
Symptoms
- Check engine light on
- Rattle from the timing cover, especially on cold start (worn chain/tensioner)
- Hard starting, rough idle, or hesitation
- Reduced power; possible limp mode
- Sometimes accompanies cam/crank sensor codes
Common causes (most → least likely)
How to diagnose it (before buying parts)
- 1 Check engine oil level and condition FIRST. Low or sludgy oil starves the VVT phasers and oil control valves and is a common, cheap cause of correlation codes.
- 2 Listen for a timing-chain rattle on cold start — a brief rattle that fades as oil pressure builds points to a stretched chain and worn tensioner.
- 3 Remove and inspect the oil control valve (VVT solenoid) and clean its screen; a clogged screen mimics phaser failure.
- 4 Use a scan tool to command the camshaft actuator and watch whether cam timing responds; no response points to a stuck phaser or OCV.
- 5 Verify the cam and crank sensors and their reluctor rings are good and the connectors are clean.
- 6 If oil, OCV, and sensors are good, measure timing-chain stretch / cam timing against spec — chain replacement is the likely fix.
Repair options & cost
By manufacturer
Timing-chain stretch on 2.0/2.4 Ecotec and some V6s is a well-known P0016 cause, often tied to skipped oil changes. Check oil and the OCV first, but be prepared for a chain job.
VVT phaser and timing-chain wear on some EcoBoost and modular engines; rattle on cold start is the classic sign. Use OEM phasers/chains.
Oil control valve and timing-chain/phaser issues appear on several GDI engines; verify oil condition and OCV operation first.
VANOS (VVT) solenoids and timing-chain issues are known correlation-code sources; clean/replace the VANOS solenoids before assuming chain wear.
Frequently asked questions
Is P0016 serious?
It can be. It often points to timing-chain stretch or a VVT phaser problem rather than a simple sensor. If a worn chain skips a tooth on an interference engine, it can cause major valve and piston damage — so don't drive it hard until you know the cause.
Can low oil cause P0016?
Yes. The variable-valve-timing phasers are oil-pressure-operated, so low or dirty oil — or a clogged oil control valve screen — can throw cam/crank correlation codes. Always check oil level and condition first; it's the cheapest possible fix.
Can I drive with P0016?
Only minimally and gently, until diagnosed. The engine may run rough or go into limp mode, and there's a risk of timing-chain-related mechanical damage. Check your oil and get it looked at promptly.
What's the difference between P0016 and a cam sensor code?
A cam sensor code (like P0340) means the signal itself is missing or bad. P0016 means both the cam and crank signals are present but out of their expected alignment — pointing more toward timing/VVT mechanical issues than a single failed sensor.
Related codes
Sources and model caveats
Code behavior and repair procedures can vary by engine, model year and calibration. Confirm the diagnosis against the vehicle's service information before replacing parts.
- Manufacturer service information
- Field diagnostic experience — replace with cited, verifiable references before publishing