P0018 - Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)
Description and meaning of DTC p0018
This diagnostic trouble code (DTC) is a generic powertrain code, which means that it applies to OBD-II equipped vehicles, including but not limited to Ford, Dodge, Toyota, VW, Honda, Chevrolet, Hyundai, Audi, Acura, etc. The crankshaft position sensor (CKP) and Camshaft position sensor (CMP) work inharmony to control the spark/fuel delivery and timing. They both consist of areluctor, or tone, ring which passes over a magnetic sensor, which generates avoltage, indicating position. The crankshaft sensor is part of the primary ignitionsystem and functions as the "trigger". It detects the position of the crankshaftrelays that information on to the PCM or the ignition module (depending on thevehicle) to control spark timing. The Camshaft position sensor detects the positionof the camshafts and relays the information to the PCM. The PCM uses the CMP signalto identify the beginning of the injector sequence. What ties these two shafts andtheir sensors together is the timing belt or chain. The cam and crank should beprecisely timed together. If the PCM detects that the crank and cam signals are outof 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. Note it is not uncommon on certain models to see this DTC in conjuction with P0008, P0009, P0016, P0017, and P0019. If you have a GM vehicle and have those multiple DTCs, check for service bulletins that may apply to your engine.
p0018 diagnostic trouble code symptoms
Symptoms of a P0018 will or may include:Malfunction Indicator Lamp (MIL) illumination The engine may run but with reduced performanceThe engine may crank but not startThe engine may exhibit a rattle near the harmonic balancer indicating the tonering is damagedThe engine may start and run, but poorly
DTC p0018 - possible causes
Causes may include:Timing chain stretched, or timing belt skipped a tooth due to wearMisalignment of timing belt/chainTone ring on crankshaft slipped/brokenTone ring on camshaft slipped/brokenBad crank sensorBad cam sensorDamaged wiring to crank/cam sensorTiming belt/chain tensioner damaged An improperly torqued crankshaft balancerA mis-built or mis-timed engineA loose or missing crankshaft balancer boltThe CMP actuator solenoid stuck openThe CMP actuator stuck in a position other than 0 degrees
How to fix OBD-II diagnostic trouble code p0018
If your vehicle is new enough that is still has powertrain warranty, please let the dealer perform the repairs. First, visually inspect the cam and crank sensors and their harnesses for damage. If you notice broken/frayed wires, repair and recheck. If you have access to a scope, check the cam and crank patterns. If a pattern ismissing, suspect a bad sensor or a slipping tone ring. Remove the cam gear and thecrankshaft harmonic balancer and inspect the tone rings for proper alignment andmake sure they're not loose or damaged or that they haven't sheared the key thataligns them. If they are properly installed, replace the sensor. If the signal appears normal, then check the timing chain/belt for properalignment. If it's misaligned, check for a damaged tensioner that may have allowedthe chain/belt to slip a tooth or several teeth. Also check that the belt/chainisn't stretched. Repair and recheck. Please consult a factory service repair manual if you need vehicle specific information.