P0018 on Mazda: How to Diagnose & Fix
Crankshaft/Camshaft Position Correlation - Bank 2 Sensor A
1 Mazda model · 1 documented issue · 1 critical · $1,500-$3,500 repair
P0018 on Mazda by model: symptoms, diagnosis and fix
The Ford-derived V6 in first-generation CX-9 (3.5L in 2007, 3.7L Duratec from 2008) suffers from timing chain stretch, typically between 80,000-120,000 miles. Chain guides and tensioners wear, causing timing to retard and triggering check engine codes. If not addressed, can lead to jumped timing and severe engine damage.
Common Symptoms
- Rattling noise on cold start from timing chain area
- Check engine light with P0016, P0017, or P0018 cam/crank correlation codes
- Rough idle and intermittent stalling
- Engine performance noticeably degraded at higher mileage
How to Fix
Replace timing chain, guides, tensioners, and cam phasers as a complete kit. This is a labor-intensive job requiring partial engine disassembly. Recommended to replace water pump and thermostat while engine is apart.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Melling 3-1047S professional timing setOEMMelling 3-1047S
Early V6 timing-set branch for 2007 3.5L, 2008-2010 3.7L and qualifying 2011 vehicles produced through December 14, 2010 Fitment/availability: Direct indexed product page identifies Melling 3-1047S for 2007-2011 CX-9, with 2007 3.5L, 200…
- Melling 3-1049SC professional timing setOEMMelling 3-1049SC
Late V6 timing-set branch for qualifying 2011 vehicles produced after December 14, 2010 through 2015 3.7L Fitment/availability: Direct indexed product page identifies Melling 3-1049SC for late-2011 through 2015 CX-9 3.7L, explicitly from…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipUse full synthetic 5W-20 oil and change every 5,000 miles to prolong chain life
- TipReplace water pump and thermostat during timing chain job - saves labor cost. CX9Club.com timing chain thread
Sources for this issue (3)
P0018 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0018 mean on a Mazda?
P0018 stands for "Crankshaft/Camshaft Position Correlation - Bank 2 Sensor A." This code means the computer detected that the crankshaft and the Bank 2 'A' (typically intake) camshaft are out of their expected timing relationship. The computer compares the crankshaft and camshaft position sensor signals; they should stay in a fixed correlation as the engine turns. When the Bank 2 camshaft is too far off from the crankshaft, P0018 sets, indicating the valve timing on that bank is misaligned. This can cause rough running, reduced power, hard starting, or a no-start, and in some cases signals timing chain or phaser trouble that warrants prompt attention. On Mazda it is documented across 1 model: CX-9.
What are the most common causes of P0018?
The most common causes of P0018 are: Stretched, worn, or jumped timing chain (Bank 2), Worn or broken timing chain guides/tensioner, Stuck variable valve timing solenoid or phaser, Low or dirty engine oil affecting the phaser, Faulty crankshaft or camshaft position sensor, Damaged reluctor/tone ring, Incorrect timing from prior service, Wiring or connector fault at a cam/crank sensor. The specific cause varies by vehicle.
How much does it cost to fix P0018 on a Mazda?
Published repair estimates on Mazda range from $1,500 to $3,500 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.