P0018
Fix within a few daysCrankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)
Code P0018 means your engine's crankshaft and camshaft (Bank 2 Sensor A) are out of sync. Common causes: Stretched timing chain (50%), faulty VVT actuator (20%), bad cam sensor (15%). Drivability: Limit driving, fix within days. Repair cost: $100-$500 DIY, $300-$2500 professional.
Can I Drive With P0018?
Limit driving, fix within a few days
Essential trips under 10 miles, avoid highways and heavy acceleration. Monitor for worsening symptoms.
Stop driving immediately if: Flashing Check Engine Light, loud engine rattling, significant power loss, engine stalling, or burning smell.
Symptoms of P0018
- 1Check Engine Light is on
- 2Engine runs rough or idles poorly
- 3Reduced engine power or acceleration
- 4Engine stalls frequently
- 5Engine is hard to start
- 6Poor fuel economy
- 7Engine noise (rattling or ticking)
Common Causes of P0018
Parts most likely causing this code, ranked by probability
A stretched timing chain or worn timing belt causes the camshaft and crankshaft to fall out of synchronization, triggering the correlation error.
50% of P0018 cases are fixed by replacing the timing chain or belt
A malfunctioning variable valve timing actuator on Bank 2 Sensor A prevents the camshaft from adjusting its position correctly, leading to a correlation mismatch.
20% of P0018 cases are fixed by replacing the VVT actuator
A faulty camshaft position sensor sends incorrect or no signal to the engine computer, making it appear as if the timing is off.
15% of P0018 cases are fixed by replacing the camshaft position sensor
Variable valve timing systems rely on clean oil and proper oil pressure to operate the cam phasers, and a lack of either can cause timing issues.
5% of P0018 cases are fixed by addressing oil pressure or changing oil
A faulty crankshaft position sensor provides inaccurate engine speed and position data, leading the computer to incorrectly detect a timing correlation error.
5% of P0018 cases are fixed by replacing the crankshaft position sensor
Frayed, corroded, or shorted wiring to the camshaft or crankshaft sensors or VVT actuators can disrupt signals and cause false correlation errors.
5% of P0018 cases are fixed by repairing wiring
Check These First (Before Buying Parts)
- Check your engine oil level and condition. Low or dirty oil can directly impact VVT system function.
- Visually inspect the wiring and connectors for the camshaft position sensor (Bank 2 Sensor A), crankshaft position sensor, and VVT actuator for any obvious damage, fraying, or corrosion.
How to Diagnose P0018
- 1Check engine oil level and condition; ensure it's full and clean.
- 2Visually inspect wiring harnesses and connectors for the camshaft position sensor (Bank 2 Sensor A), crankshaft position sensor, and VVT actuator for damage or corrosion.
- 3Use a professional scan tool to monitor live data for camshaft and crankshaft position sensor readings to identify any discrepancies.
- 4Perform a physical inspection of the timing chain or belt for signs of stretch, slack, or wear, if accessible.
- 5Test the camshaft position sensor (Bank 2 Sensor A) and crankshaft position sensor for proper operation using a multimeter or oscilloscope.
- 6Test the VVT/VCT actuator (cam phaser) for proper electrical function and mechanical movement.
P0018 on Popular Vehicles
Chevrolet Traverse
2009-2017P0018 on these models, particularly with the 3.6L V6 engine, is frequently caused by a stretched timing chain. Regular oil changes with the correct oil viscosity are critical for prevention.
60% fixed by replacing timing chain components
Ford F-150
2011-2017Ford F-150s with the 3.5L EcoBoost engine can experience P0018 due to timing chain stretch or faulty VVT cam phasers. These engines are sensitive to oil quality and maintenance.
55% fixed by timing chain/phaser replacement
Honda Accord
2008-2012While less common than on GM or Ford, P0018 on Honda V6 engines can sometimes point to a faulty VVT oil control valve (solenoid) or a failing camshaft position sensor, often related to sludge buildup.
40% fixed by VVT actuator replacement
Frequently Asked Questions
What does P0018 mean?
P0018 indicates that your engine's computer has detected a mismatch in the rotational positions of the crankshaft and the camshaft on Bank 2, Sensor A. This means the engine's timing is off.
Can I drive with P0018?
Limit driving, fix within a few days. Driving with a P0018 code can lead to serious engine damage if the timing is significantly off. If your Check Engine Light is flashing, or you notice severe symptoms like stalling or loud engine noises, stop driving immediately.
Will P0018 clear itself?
No, P0018 will not clear itself. This code points to a mechanical or electrical issue that requires diagnosis and repair. The engine computer will continue to detect the timing correlation error until the underlying problem is fixed.
How do I fix P0018 myself?
Start by checking your engine oil level and condition. If that's not the issue, inspect wiring to the camshaft and crankshaft sensors. If those are good, you might need to replace the camshaft position sensor (Bank 2 Sensor A) or the VVT actuator. A stretched timing chain requires advanced mechanical skills.
How much does it cost to fix P0018?
DIY costs range from $100-$500 for sensors or VVT actuators. Professional repair costs can be $300-$800 for sensors/actuators, but a timing chain replacement can cost $1,000-$2,500 or more due to extensive labor.
P0018 keeps coming back - why?
If P0018 keeps returning, the initial repair likely didn't address the root cause. Common reasons for recurrence include a misdiagnosis (e.g., replacing a sensor when the timing chain is stretched), underlying oil pressure issues affecting VVT, or a faulty engine computer.
Will P0018 fail emissions/smog test?
Yes, P0018 will cause your vehicle to fail an emissions or smog test. Any active Check Engine Light indicates a fault in the emissions system or related components, preventing the vehicle from passing inspection.
What's the difference between P0018 and P0016?
P0018 refers to a correlation issue between the crankshaft and camshaft on Bank 2, Sensor A (typically the intake camshaft on the cylinder bank that doesn't contain cylinder #1). P0016 refers to the same issue but on Bank 1, Sensor A (the intake camshaft on the cylinder bank that contains cylinder #1).
P0018 on GM 3.6L V6 engines?
P0018 is a common code on GM vehicles with the 3.6L V6 engine (e.g., Chevrolet Traverse, GMC Acadia, Buick Enclave), often indicating a stretched timing chain. This engine is known for timing chain wear, especially with extended oil change intervals.
Questions to Ask Your Mechanic
Did you check the engine oil pressure and condition before diagnosing?
Good answer: Yes, we confirmed the oil level is correct and the oil is clean. Low oil pressure or dirty oil can directly impact VVT system operation.
What were the live data readings for the camshaft and crankshaft position sensors?
Good answer: We monitored the cam and crank sensor signals on the scan tool. The Bank 2 Sensor A camshaft position showed a consistent deviation of X degrees from the crankshaft, indicating a timing issue.
Have you inspected the timing chain or belt for stretch or wear?
Good answer: Yes, we performed a visual inspection through the access points and found noticeable slack in the timing chain, consistent with a stretched chain.
Repair Cost Estimate
DIY Repair
Parts only
$100-$500
Shop Repair
Parts + labor
$300-$2500
Save $200-$2000 by doing it yourself, depending on the cause
Difficulty
intermediate
Time
2-15 hours
Intermediate. While checking oil and sensors is straightforward, diagnosing and replacing timing chains or VVT actuators requires specialized tools and significant mechanical experience.
Cost of Waiting
Ignoring P0018 can lead to catastrophic engine damage, including bent valves, damaged pistons, or complete engine failure, turning a potential $500 repair into a $3,000-$7,000 engine replacement. Continued misfires can also destroy your catalytic converter ($800-$2,500 repair).
While You're In There...
If the VVT system is affected by oil quality or pressure, a fresh oil change is a critical first step and good maintenance.
If you are accessing camshaft sensors or VVT actuators, you will likely remove the valve cover, making it smart to replace the gasket to prevent future oil leaks.
If replacing a stretched timing chain, it's essential to replace all related components like tensioners, guides, and sprockets as they wear together and prevent repeat labor.
Tools You'll Need
- OBD-II scan tool with live data capability
- Basic hand tools (sockets, wrenches, screwdrivers)
- Multimeter
- Engine oil and filter (if oil related)
- Torque wrench
- Possibly specialized timing tools (for timing chain replacement)
P0018 is a serious code that needs attention, but it's a known issue for many vehicles. With proper diagnosis, you can get your engine running smoothly and prevent costly damage.
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Your Next Steps
Step 1: Check your engine oil. Ensure it's at the correct level and clean. If it's low or dirty, change it and clear the code to see if it returns.
Step 2: If the oil is good, visually inspect the wiring to the camshaft position sensor (Bank 2 Sensor A), crankshaft position sensor, and VVT actuator for any damage. Repair any frayed or corroded wires.
Step 3: If wiring is good, use a scan tool to monitor live data for cam/crank correlation. If the correlation is consistently off, consider replacing the camshaft position sensor (Bank 2 Sensor A) or the VVT actuator. If the issue persists, a timing chain inspection is necessary.