The P0018: Crankshaft Position – Camshaft Position Correlation (Bank 2 Sensor A) indicates a problem with the timing relationship between the crankshaft and the camshaft on Bank 2 of the engine. This condition can be caused by various factors, including a misaligned timing chain or belt, faulty sensors, or problems with the engine’s variable valve timing system.
P0018 quick overview
Meaning | P0018: Crankshaft Position – Camshaft Position Correlation (Bank 2 Sensor A) |
Is it serious? | Yes, this code is serious as it may lead to poor engine performance, increased fuel consumption, or engine damage if not addressed promptly. |
Possible causes | – Timing chain or belt misalignment – Faulty camshaft position (CMP) sensor – Malfunctioning crankshaft position (CKP) sensor – Stretched timing chain or worn timing components – Engine oil issues, including low level or incorrect viscosity – Variable Valve Timing (VVT) solenoid or actuator failure |
How to diagnose? | Inspect Timing Components: Check the alignment of the timing chain or belt. Test Sensors: Test the CMP and CKP sensors for proper operation. Evaluate Engine Oil: Check the oil level and viscosity. Scan for Additional Codes: Look for other codes that may indicate related issues. Monitor Sensor Data: Use a scan tool to compare the real-time data of the CMP and CKP sensors. Check VVT System: Inspect the VVT solenoid and actuator for proper function. Visual Inspection: Look for signs of wear or damage on timing components. |
P0018 Meaning
This code means there’s a timing problem in your engine. It’s like the engine’s rhythm is off, causing it to run poorly. This can happen if the parts that keep the engine’s timing in check – like the timing belt or chain – are not working right, or if there’s a problem with the sensors that tell the engine how to run. It’s important to get this fixed to keep your engine running smoothly and avoid bigger problems.
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How to fix P0018 – learn from mechanics
I looked into P0018 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.
Case #1: Subaru
Vehicle Information: 2006 Subaru B9 Tribeca Limited 3.0L
Issue + Repair History:
- Codes P0011 and P0021 indicated camshaft position timing over-advance for both banks.
- Reported spark knock under hard acceleration and MIL illuminating after three drive cycles.
- Additional codes P0016 and P0018 appeared with extended driving.
- Underwent multiple oil changes and flushes, replacement of both banjo bolts with filters, and testing of all four solenoids.
- Previously diagnosed at a local Subaru dealer, suggesting a faulty left solenoid.
Suggestions to Fix Issue:
- Check if the timing chain has jumped.
- Test oil pressure and inspect chain tension.
- Ensure correct oil viscosity is being used.
- Consider possible slack in the timing chains and check compression.
Final Fix:
- Resolved by disassembling timing components and finding a missing bushing in the lower idler gear, causing chain tension loss. After addressing this, the problem was fixed.
Case #2: Hyundai
Vehicle Information: 2008 Hyundai Santa Fe GLS 2.7L
Issue + Repair History:
- Check engine light on with codes P0016 and P0018 for CKP-CMP correlation issues.
- Vehicle has 55,078 miles and clean 5W-20 oil.
- Experienced extremely cold temperatures, dropping to -20 degrees.
Suggestions to Fix Issue:
- Check if the timing belt has jumped a tooth or if the hydraulic tensioner is weak.
- Scope sensors to check for clean patterns.
- Verify if the model has updated actuator/phaser for these specific codes.
- Consider the possibility of the timing belt jumping due to cold weather affecting the tensioner.
- Investigate if the Oil Control Valve (OCV) solenoids are causing the issue.
- Ensure a factory oil filter is used and retest.
- Graph “desired” and “actual” cam positions at idle to check for timing issues or sluggish response, indicating oil pressure/flow problems.
Final Fix:
- Discovered the front and rear cams were off by two teeth each.
- The timing belt tensioner was fully extended, suggesting the belt was stretched.
- Replacing the timing belt resolved the issue.
Case #3: Land Rover
Vehicle Information: 2016 Land Rover Range Rover Sport Supercharged 5.0L
Issue + Repair History:
- Check engine light on with codes P0016 and P0018 indicating issues with Bank 1 and Bank 2 intake cam timing.
- Recent work performed at another shop, including replacement of timing chains, guides, tensioners, actuators, and valve job.
- Despite using factory parts and tools, the engine sets codes immediately upon starting.
Suggestions to Fix Issue:
- Consensus among responses is that the timing is likely off. This is a common error that occurs even when the technician is confident in their work.
- Suggestion to take apart the engine again to verify and correct timing.
- Recommendations to perform a cylinder pressure waveform test and check idle vacuum to confirm if the timing is indeed off.
Final Fix:
- Upon re-inspection, it was found that the chains were off by one tooth due to not taking all the slack out during the installation.
- Correcting the timing chain alignment resolved the issue.
Case #4: Jeep
Vehicle Information: 2011 Jeep Grand Cherokee Laredo 3.6L
Issue + Repair History:
- The vehicle displayed code P0018 for camshaft position correlation.
- Previous work at another shop included replacing the left intake and exhaust camshaft phaser, timing chain, guides, tensioners.
- Despite the work, the P0018 code persisted.
- The vehicle was disassembled and rechecked for timing, which appeared correct.
- Crank/Cam relearn was performed but did not resolve the issue.
Suggestions to Fix Issue:
- Check for oil plugs that may be loose or fallen out.
- Consider issues with oil pressure to the phaser, potentially due to loose galley bolts.
- Suggestions to replace or test the exhaust camshaft for defects.
- Verify oil supply to phasers and check if aftermarket oil filters are causing issues.
Final Fix:
- The solution involved replacing the exhaust camshaft, which resolved the problem.
Case #5: Toyota
Vehicle Information: 2008 Toyota Sequoia Limited 5.7L
Issue + Repair History:
- The vehicle displayed the P0018 code (Bank 2 intake cam to crank correlation).
- Oil level and condition were good, and the engine was running smoothly.
- Possibilities included a jumped timing chain or a PCM issue, but these were unlikely due to the engine’s good condition.
- Swapped cam sensors between intake and exhaust on bank 2, but no change in code.
- Code would not return until after 4-5 drive cycles.
Suggestions to Fix Issue:
- Swap the oil control valves and test drive.
- Check with a scope or consider pulling the timing chain cover.
- Scope the crank and cam sensors simultaneously and compare with a known good waveform.
- Suggestion to add Marvel Mystery Oil to the engine oil and idle, then change oil and filter.
- Consider the possibility of a sticking cam actuator or solenoid.
Final Fix:
- Swapping the actuator solenoids led to the disappearance of the problem.
- A different issue with the air injection valve emerged, leading to a dealer visit for warranty repairs.
- The original P0018 code did not return, resolving the initial issue.
You can also check P0016. as it commonly companies the P0018.
How to diagnose P0018
I made you an overview of solving this DTC, based on all the advice that was suggested by certified mechanics to address this issue in previously mentioned service cases.
Advice | Description of Diagnostic Step |
---|---|
Check Timing Chain or Belt | Verify if the timing chain or belt is correctly aligned; a misalignment can cause the code. |
Inspect Camshaft Actuators/Solenoids | Evaluate the condition and operation of camshaft actuators or solenoids; they may be sticking or malfunctioning. |
Use a Scope on Sensors | Scope the crank and cam sensors simultaneously for proper correlation. |
Inspect Oil Control Valves | Check the oil control valves, which might be causing the issue; consider swapping them. |
Consider PCM Issue | Evaluate if the PCM is processing information correctly, as it could be a rare cause. |
Perform a Smoke Test | Conduct a smoke test to check for any vacuum leaks that could lead to the code. |
Evaluate Fuel Trim Data | Monitor fuel trim data for indications of lean or rich conditions that could trigger the code. |
Check Engine Oil Quality | Ensure the engine oil is of the correct type and quality; poor oil can affect engine performance and sensor readings. |
Look for Related TSBs | Search for Technical Service Bulletins (TSBs) related to the specific code and vehicle model. |
Car Diagnostics Training
- Car Electrical basics
- OBD-II scanner basics
- How to use an OBD reader
- Introduction to a Bi-directional Scan tool
- OBD scanner buyer’s guide + discounts
I test OBD-II scanners and make DIY Engine diagnostics guides to help you solve your car problems without having to depend on the mechanic. A lot of them will try to scam you or are just no help at all. About Juraj Lukacko