Is your car engine stalling and not starting? Is there an increase in the fuel consumption? Have you lost the response from the engine with sudden downfall in acceleration? All these can be an indication towards P0018.
OBD-II Code P0018 is defined as a Crankshaft Position – Camshaft Position Correlation.
What Does Code P0018 Mean?
Diagnostic trouble code (DTC) P0018 stands for “Crankshaft Position- Camshaft Position Correlation (Bank 2, Sensor A).” It is set when the camshaft(s) on bank 2 of the engine is not in its proper position in relation to the crankshaft.
The “Bank 2” in this definition refers to the side of the engine that does not contain the number one cylinder. Meanwhile, the “Sensor A” refers to the intake camshaft sensor.
The ECM/PCM detects any out-of-time situation involving the crankshaft and camshaft (for example, greater than 9 degrees on a GM) and sets trouble codes like P0018.
The crankshaft sensor is part of the primary ignition system and functions as the “trigger”. It detects the position of the crankshaft and passes that information on to the PCM or the ignition module to control spark timing.
The Camshaft position sensor detects the position of the camshafts and sends the information to the PCM.
The PCM uses the CMP signal to identify the beginning of the injector sequence. What ties these two shafts and their sensors together is the timing belt or chain. The cam and crank should be precisely timed together.
If the PCM detects that the crank and cam signals are out of time by a specific number of degrees, this DTC will set. Bank 2 is the side of the engine that doesn’t contains cylinder #1, the “A” sensor is most likely the intake camshaft side.
Potential Causes of a P0018 Code
Causes may include as below :
- The timing chain stretched, or timing belt skipped a tooth due to wear.
- Misalignment of timing belt/chain.
- The tone ring on the crankshaft slipped/broken.
- The tone ring on the camshaft slipped/broken.
- Bad crank & cam sensor.
- Damaged wiring to crank/cam sensor.
- Timing belt/chain tensioner damaged.
- An improperly torqued crankshaft balancer.
- A loose or missing crankshaft balancer bolt.
- The CMP actuator solenoid stuck open.
- The CMP actuator stuck in a position other than 0 degrees.
P0018 Code Symptoms
Symptoms of a P0018 may include as below:
- Malfunction Indicator Lamp (MIL) illumination.
- The engine may run but with reduced performance.
- The engine may crank but not start.
- The engine may exhibit a rattle near.
- The harmonic balancer indicating.
- The tone ring is damaged.
- The engine may start and run, but poorly.
How to Fix P0018
First, visually inspect the cam and crank sensors and their harnesses for any damage.
If you find broken or frayed wires, repair them and recheck. If you have access to a scope, check the cam and crank patterns. If a pattern is missing, suspect a faulty sensor or a slipping tone ring.
Remove the cam gear and crankshaft harmonic balancer to inspect the tone rings for proper alignment and ensure they are not loose, damaged, or sheared the alignment key.
If they are installed correctly, replace the sensor. If the signal appears normal, then check the timing chain/belt for proper alignment. If it is misaligned, check for a damaged tensioner that may have allowed the chain/belt to slip a tooth or multiple teeth. Also, check if the belt/chain is stretched. Repair and recheck.
How Much Does It Cost to Fix a P0018 Code?
To fix a P0018 code, which indicates a crankshaft position – camshaft position correlation issue, you can expect to pay between $200 and $500 depending on the specific cause and the labor costs in your area, with the main cost likely coming from replacing a faulty camshaft position sensor or variable valve timing solenoid, along with the necessary labor to access and replace the part.