What P0016 Means
P0016 flags a crankshaft position (CKP) to camshaft position (CMP) correlation fault on Bank 1, sensor A. The PCM uses the crankshaft sensor to know exactly where the pistons are in their stroke, and the camshaft sensor to know whether each cylinder is on its intake, compression, power, or exhaust stroke — together they let the ECU fire the correct injector and spark plug at the correct moment. P0016 means these two signals no longer line up within the expected window, which the PCM interprets as either a timing chain that has jumped a tooth, a camshaft actuator holding an incorrect position, or a sensor reporting bad data. Because this code directly affects ignition and injection timing, it's rated higher severity than most sensor codes — a serious mismatch can cause the engine to run badly, stall, or in worst cases, cause piston-to-valve contact on interference engines if the timing chain has actually skipped. It's one of the few OBD-II codes where continuing to drive on worn timing components carries genuine risk of expensive engine damage.
Common Causes
- Timing chain or belt that has stretched, or jumped a tooth on the crankshaft or camshaft sprocket
- Worn timing chain guides or a failed tensioner allowing excess chain slack
- Faulty camshaft or crankshaft position sensor giving an inaccurate or noisy signal
- Damaged reluctor ring/tone wheel on the crankshaft or camshaft
- Failing VVT phaser unable to hold commanded camshaft position
- Wiring damage, corrosion, or a poor connector ground affecting either sensor's signal
Symptoms You Might Notice
- Check Engine Light on, often alongside rough running or a noticeable loss of power
- Engine cranks but starts hard, or occasionally fails to start at all
- Rattling or slapping noise from the timing cover area, especially on startup
- Random or intermittent misfires as ignition timing drifts out of sync
- Stalling at idle or under light load in more advanced cases
What to Check First
- 1
Retrieve freeze-frame data to see engine speed and load conditions when the fault was set, which helps narrow down whether it's sensor-related or mechanical
- 2
Visually and audibly inspect for timing chain noise with the engine running, which can indicate excessive slack
- 3
Check camshaft and crankshaft sensor wiring and connectors for damage or corrosion before assuming a mechanical fault
- 4
Use a scan tool capable of graphing cam/crank correlation live data to see the actual degree of misalignment
- 5
If mechanical timing is suspected, a technician will need to remove the timing cover to physically verify chain and sprocket alignment against factory timing marks
Frequently Asked Questions
Can I keep driving with P0016?
This isn't a code to ignore. If the underlying cause is a stretched or skipped timing chain, continuing to drive risks serious internal engine damage, particularly on interference engines. Get it diagnosed as soon as possible rather than waiting.
Is P0016 always a timing chain problem?
Not always — a faulty cam or crank sensor can trigger the same code without any actual mechanical timing fault. That's why checking sensor wiring and signal quality first, before assuming the chain has jumped, is the correct diagnostic order.
How much does fixing P0016 typically cost?
If it's a sensor, the repair is relatively affordable. If it's a genuinely stretched or jumped timing chain, the repair involves substantially more labor to access and correct, since the timing cover, and sometimes the front of the engine, has to come apart.
Reviewed by Emmanuel Erere, Auto Mechanic. Causes and diagnostic steps checked for workshop accuracy.