What does the P0018 fault code mean?
The P0018 fault code, applicable to all car manufacturers, means “Crankshaft Position – Camshaft Position Correlation (Bank 2, Sensor A)“.
Background Information: The crankshaft converts the up-and-down motion of the pistons into rotational motion. The camshaft controls the opening and closing of the valves. The Electronic Control Unit (ECU) continuously monitors the timing position of the variable camshaft, checking the relative position between the camshaft and crankshaft. If the relative position is misaligned by more than one gear tooth, this fault code will appear. Possible causes include a faulty camshaft position sensor or its circuitry, a faulty crankshaft position sensor or its circuitry, a faulty engine speed sensor, contaminated engine oil, or a stuck variable camshaft solenoid valve.
P0018 Error Code Symptoms
- Difficulty starting the engine
- Unstable idle
- Loss of power during acceleration
- Misfires
- Increased fuel consumption
- Check engine light illuminated
- Poor traction at high RPMs
Important! Sometimes the P0018 error only appears under specific conditions, such as engine overheating or changes in engine speed.
Main Causes of P0018 Error Code
- Worn or stretched timing chain/belt
- Faulty camshaft position sensor
- Problems with the crankshaft position sensor
- Variable Valve Timing (VVT) errors or malfunctions
- Mechanical damage to the timing sprocket
- Clogged oil passages in the VVT solenoid valve
P0018 Error Code in Different Vehicles
Here is an overview of how the P0018 error manifests in major manufacturers:
P0018 in BMW: This error is usually related to the VANOS system. The problem may be caused by solenoid valve contamination or aged engine oil. Diagnosis requires connecting proprietary software (INPA, ISTA).
P0018 in Toyota: It appears in models equipped with VVT-i engines. The main cause is usually a stretched belt/chain or a loose tensioner.
P0018 in Hyundai/Kia: It is common in the GDI engine series. The code usually appears when the CVVT malfunctions or the oil passages are clogged.
P0018 in Ford: In vehicles equipped with the Ti-VCT system, the error may be due to wear or improper installation of the timing chain after repairs.
P0018 in Mercedes-Benz: Usually related to the phase shifting system, shaft position sensor problems, or oil system contamination.
How to Diagnose P0018 Error Code?
Step 1: Read the error code using an OBD2 scanner.
Step 2: Check for other related codes (e.g., P0016 to P0025).
Step 3: Visually inspect the condition of the timing chain or belt – look for signs of stretching, wear, or damage.
Step 4: Compare the signals of the CKP and CMP sensors using an oscilloscope or diagnostic tool.
Step 5: Check the performance of the VVT system – solenoid valves, oil pressure, oil passages.
Possible Causes and Diagnostic Methods
| Possible Cause | How to Check？ |
|---|---|
| Timing chain/belt wear | Check physical condition, noise, and markings |
| Faulty CMP sensor | Check waveform with a scanner |
| CKP sensor issue | Check signal on oscilloscope |
| VVT malfunction | Diagnose using OBD2 scanner and solenoid testing |
| Low oil pressure | Measure pressure, check oil level and oil condition |
Tools needed: Car fault code reader (preferably with graphical analysis support), multimeter, oscilloscope (if possible), mechanical oil pressure gauge, wrench set for removing timing components, probes and cleaning fluid
How to fix P0018 error code? (Solutions to the problem)
Simple troubleshooting methods
- Clean and reconnect CKP and CMP sensor connectors
- Reset the error, test drive to check if the fault code reappears
- Check the oil level and replace if necessary
- If contamination is suspected, replace the engine oil and oil filter
- Replace the crankshaft or camshaft position sensor if it is out of specification
In-depth diagnostic and repair solutions
- Inspection and possible replacement of the timing chain or belt
- Replacement of worn or damaged sprockets on the shafts
- Flushing or replacing the VVT solenoid valve
- Precise valve timing setting provided by Marks
- Resynchronization after parts repair or replacement
Troubleshooting by symptoms
| Symptom | Possible Solution |
|---|---|
| Misfire, backfire | Check and adjust timing phase |
| Unstable idle | CMP/CKP sensor verification |
| Morning starting problems | Check oil pressure |
| High fuel consumption | VVT system diagnosis |
| Permanent error P0018 | Check the entire synchronization system |
P0018 Error Frequently Asked Questions
Is it possible to continue driving with a P0018 error?
It is not recommended, as timing violations can cause serious engine damage and reduce its lifespan.
Could the P0018 error be caused by old engine oil?
Yes, dirty or thick oil can interfere with the phase change system (VVT), leading to timing errors.
Can you reset the P0018 error yourself?
Yes, using an OBD2 scanner or temporarily disconnecting the battery, but the error will reappear if the cause of the fault is not eliminated.
Do I need to replace the timing chain if I have a P0018 error code?
Not necessarily. However, if the chain is stretched, has excessive play, or the components are worn, the chain must be replaced to restore proper timing.
Does the P0018 error affect fuel consumption?
Yes, impaired ignition timing reduces combustion efficiency, leading to increased fuel consumption.
Related OBD2 Error Codes:
P0016 – Crankshaft Position – Camshaft Position Correlation (Bank 1, Sensor A)
P0017 – Crankshaft Position – Camshaft Position Correlation (Bank 1, Sensor B)
P0019 – Crankshaft Position – Camshaft Position Correlation (Bank 2, Sensor B))
If you are not confident in your abilities, please contact a professional mechanic. Accurately identifying the cause of the error is crucial, as a small malfunction can lead to expensive repairs in the future.