P0018 Code Fix: Crankshaft–Camshaft Correlation (Bank 2, Sensor A)

By iCarsoft Team

ENGINE TIMING · CRANK/CAM CORRELATION · DTC P0018

P0018 Code Fix: Crankshaft–Camshaft Position Correlation (Bank 2, Sensor A)

Code P0018 means your engine's computer has caught the crankshaft and the Bank 2 "A" camshaft spinning out of sync — their position signals don't correlate the way correct timing demands. It's a serious one: it usually points to a stretched timing chain, a worn tensioner, or a failing crank/cam sensor, and it can cause hard starting, stalling, and lost power. This guide explains what P0018 means, what causes it, how to diagnose it with a scan tool and a look at the timing system, realistic repair costs, and how to fix and clear it.

Severity

High

Drivable?

Not Advised

Avg Repair

$100–$1,500

DIY Level

Intermediate

If your scan tool returned P0018 — Crankshaft Position - Camshaft Position Correlation (Bank 2, Sensor A), the ECM compared the crankshaft and the Bank 2 intake ("A") camshaft position signals and found them out of agreement beyond the allowed tolerance (often more than about 5 degrees). "Bank 2" is the side of the engine that doesn't contain cylinder #1. Because correct timing is everything, the most common causes are mechanical — a timing chain that's jumped a tooth or a worn tensioner — or a crank/cam sensor sending bad data.

What Does P0018 Mean?

The crankshaft position sensor (CKP) and the camshaft position sensor (CMP) constantly report where the crank and cam are. The ECM uses that relationship to time ignition and fuel injection and to control variable valve timing. When the two signals drift apart — the cam isn't where the crank says it should be — the ECM sets P0018.

P0018 is a generic OBD-II powertrain code defined under the SAE J2012 standard. The "(Bank 2, Sensor A)" part tells you which sensor pair is involved: the "A" (usually intake) camshaft on Bank 2. It's a correlation code, which matters — it usually means the sensors are working and accurately reporting that the camshaft is mechanically out of sync, rather than the sensor itself being dead.

It belongs to a family of timing-correlation codes — P0016 (Bank 1, Sensor A), P0017 (Bank 1, Sensor B), and P0019 (Bank 2, Sensor B). Seeing several together points strongly at the timing chain or oil/VVT system rather than one sensor.

Diagram showing how the crankshaft and camshaft position sensors work together to keep engine timing in sync, the relationship P0018 monitors — The CKP and CMP sensors track crank and cam position; P0018 fires when the two no longer correlate.

Pro insight: Correlation usually means mechanical. Because the sensors are typically reporting the truth, start by suspecting the timing chain, tensioner, and oil condition — not the sensor. A quick check: compare crank-to-cam deviation in live data; it should sit within a few degrees. A large, steady offset almost always means the chain has stretched or jumped a tooth.

Symptoms of P0018

P0018 usually makes itself known, and the OBD-II system (mandated by the California Air Resources Board) will light the dash. Watch for:

Reduced engine performance — noticeable power loss on acceleration from incorrect ignition timing.
Unstable idle or stalling — shaky idle, RPM swings, or stalling at stops.
Hard starting or no-start — especially when cold, from misaligned crank and cam signals.
Check Engine Light — set when the ECM detects the correlation error.
Poor fuel economy — inefficient combustion as timing slips.
Timing-chain rattle — a metallic rattle on start-up can accompany a stretched chain.

Commonly Affected Vehicles

P0018 is most common on engines with variable valve timing. Frequently reported examples include the Ford F-150 (2011–2016, timing-chain slack), Honda Accord (2013–2017, failed camshaft sensor), Chevrolet Silverado (2014–2018, crank-sensor interference), BMW 3 Series F30 (2012–2016, timing-chain tensioner), and Toyota Camry (2015–2019, ECM software). The fault behaves similarly across makes.

The Most Common Root Causes (Ranked)

Because P0018 is a correlation code, the cause is more often mechanical than electrical. Here's the realistic distribution.

Likelihood	Cause	Why it happens
~35%	Stretched or jumped timing chain/belt	A worn chain stretches or skips a tooth, physically shifting the cam relative to the crank.
~25%	Worn tensioner or guides	A failed tensioner or worn guides let the chain slacken, throwing off cam timing.
~20%	Faulty camshaft (CMP) sensor	A worn or moisture-damaged CMP sensor sends inaccurate position data to the ECM.
~12%	Faulty crankshaft (CKP) sensor or wiring	Contamination, a bad reluctor ring, or wiring issues make the crank signal fluctuate.
~8%	ECM software or hardware issue	Rare. Outdated firmware can misread the signals; only suspect it after the mechanical checks pass.

Close-up of a crankshaft position sensor, one of the components tested when diagnosing a P0018 correlation code — A contaminated or failing crank/cam sensor can also break correlation — test it before condemning the timing chain.

Step-by-Step Diagnostic Procedure

Work from the data inward: confirm the deviation, inspect the obvious, then test sensors and the timing system before opening anything up. Plan on 1–2 hours for diagnosis.

Step 1 — Read codes & live data. Connect a capable scan tool such as the iCarsoft CR MAX or CR Eagle, retrieve P0018 and any companions, and check the crank-to-cam correlation deviation — it should be under about 5 degrees. A reading like 15 degrees confirms a real timing offset. Verify VVT operation while you're there.

Step 2 — Visual inspection. Look for timing chain/belt slack, oil or damage on the sensors, and wear or breakage on the tensioner and guides. A loose tensioner bolt alone can cause misalignment.

Step 3 — Test the CKP & CMP sensors. Measure resistance with a multimeter (typically 200–1000 ohms per the manual) and use an oscilloscope to confirm a clean, stable waveform. An infinite resistance reading means the sensor is open.

Step 4 — Inspect the timing system. Remove the timing cover and check the alignment marks on the chain/belt, and test tensioner pressure against spec. This is where a jumped tooth shows up.

Step 5 — Verify the ECM. If everything mechanical and electrical checks out, update the ECM firmware or test with a known-good unit — outdated software occasionally triggers false correlation codes.

Step 6 — Repair & recalibrate. Fix the root cause, clear the codes, recalibrate timing where required, and road-test to confirm P0018 stays off.

Replacing timing components and crank/cam sensors to repair a P0018 crankshaft-camshaft correlation fault — Most P0018 repairs come down to the timing chain and tensioner, or a crank/cam sensor — always use OEM parts.

Realistic Repair Cost Breakdown

Costs swing widely because P0018 can be a cheap sensor or a full timing-chain job. Figures below reflect typical 2025–2026 US rates and combine parts and labor.

Repair	Typical Cost (USD)
Professional diagnosis	$75–$150
CMP / CKP sensor replacement	$100–$300
Tensioner / guides	$200–$500
Timing chain / belt job	$500–$1,500
ECM software update	$0–$150

Watch out: driving on a stretched timing chain risks it jumping further or breaking — which can bend valves and cause major engine damage. Treat P0018 as urgent.

iCarsoft CR MAX bi-directional diagnostic scan tool for reading crank and cam correlation data to diagnose P0018

PRO WORKSHOP TOOL

Why the iCarsoft CR MAX & CR Eagle make P0018 easier

A basic reader confirms P0018 but can't show you how far out of sync the engine is. The iCarsoft CR MAX and CR Eagle stream live crank and cam data so you can read the actual correlation deviation and decide between a sensor, the wiring, or the timing chain before you start wrenching.

Live crank/cam correlation data — see the deviation in degrees and confirm a real timing offset.
Full-system & bi-directional — check VVT operation and actuate components, not just read codes.
Read and clear codes plus freeze-frame to capture the conditions when P0018 set.
Broad multi-brand coverage — Ford, Honda, GM, BMW, Toyota, and more.
Confirm the repair and clear the code once the signals line up again.

Shop CR MAX → Shop CR Eagle →

Preventive Maintenance — Keep P0018 From Coming Back

Replace the timing chain/belt on schedule — follow the manual; a fresh chain is the best insurance against correlation codes.
Inspect the CKP and CMP sensors periodically — roughly every 20,000 km, checking for oil contamination and secure connectors.
Avoid prolonged high-load operation — it accelerates timing-system wear.
Keep up with oil changes — clean oil keeps VVT actuators and tensioners working correctly.
Scan regularly — catch timing drift early before it becomes a jumped chain.

Routine timing-system and sensor maintenance that helps prevent the P0018 crankshaft-camshaft correlation code — Scheduled timing-component service and regular scans are the surest way to keep P0018 from returning.

Frequently Asked Questions

What does P0018 mean?

It means the ECM found the crankshaft and the Bank 2 "A" camshaft out of sync — their position signals don't correlate within tolerance, usually because of a timing or sensor problem.

Is it safe to drive with a P0018 code?

It's not advised. The engine may stall or be hard to start, and if the cause is a stretched timing chain, continuing to drive risks serious engine damage. Diagnose it promptly.

What's the difference between P0016, P0017, P0018, and P0019?

They're the same crank/cam correlation fault on different sensors: P0016 is Bank 1 Sensor A, P0017 is Bank 1 Sensor B, P0018 is Bank 2 Sensor A, and P0019 is Bank 2 Sensor B.

What usually causes P0018?

Most often a stretched or jumped timing chain or a worn tensioner, followed by a faulty camshaft or crankshaft sensor. Because it's a correlation code, the fault is usually mechanical.

Can I just replace the sensor?

Sometimes, but don't assume. Test the crank and cam sensors and check the timing chain first — replacing a sensor won't fix a stretched chain, which is the more common cause.

How do I clear P0018?

Repair the underlying cause, recalibrate timing if required, then clear the code with a scan tool and road-test. If the root problem isn't fixed, the code will return.

Bottom Line

P0018 tells you the crankshaft and the Bank 2 "A" camshaft have fallen out of sync — and because it's a correlation code, the sensors are usually right and the problem is mechanical. Read the actual deviation in live data, inspect the timing chain, tensioner, and oil, and test the crank and cam sensors before replacing anything. Most fixes come down to timing components or a sensor, always with OEM parts. Diagnose it with a capable tool like the CR MAX or CR Eagle, repair the real cause, recalibrate, and clear the code — and don't put it off, since a slipping chain can do expensive damage.