Technical Description of OBD-II Trouble Code
The code indicates a range/performance issue with the Camshaft Position Sensor A Circuit in Bank 2. This is a generic diagnostic trouble code (DTC) that applies to vehicles manufactured from 1996 onwards. While it is commonly seen in Toyota, Lexus, Hyundai, Audi VW Volkswagen, Chevrolet, Scion, and Ford vehicles, it can affect any make of vehicle. The troubleshooting steps will vary depending on the specific vehicle.
The P0346 code signifies a problem with the camshaft signal “A” for bank 2, which refers to the bank of cylinders in the engine that does not include cylinder #1.
Description and correlation of the crankshaft and camshaft position sensors
In modern vehicles, it is important to understand the function and interaction of these sensors. Distributorless ignition vehicles use a crank and cam sensor instead of an electronic distributor module and trigger wheel.
The crankshaft position sensor (CPS) informs the engine control module about the position of the pistons relative to top dead center, enabling fuel injection and spark plug firing. The camshaft position sensor (CMP) indicates the position of the camshaft intake lobe in relation to the CPS signal and the opening of the intake valve for fuel injection in each cylinder.
Description and location of sensors
Both the crank and cam sensors provide an “on and off” signal and can be either hall effect or magnetic sensors.
A hall effect sensor utilizes an electromagnetic sensor and a reluctor. The reluctor resembles a picket fence with small cups and squares cut out of the sides. While the reluctor spins, the sensor remains stationary and mounted close to it. Each time a post passes in front of the sensor, a signal is produced, and the signal turns off when the post passes.
A magnetic pickup consists of a stationary sensor and a magnet attached to the rotating part. Whenever the magnet passes in front of the sensor, a signal is produced.
Locations
A hall effect crank sensor is typically located on the harmonic balancer at the front of the engine. The magnetic pickup can be found on the side of the engine block, using the center of the crankshaft as a signal, or in the bellhousing, utilizing the flywheel as a trigger. The camshaft sensor is mounted either at the front or rear of the camshaft. In the case of P0346, it specifically refers to bank 2, which does not include cylinder #1.
Symptoms
The vehicle will likely continue to run with this code, as it is often intermittent. The powertrain control module (PCM) can often operate the vehicle in “limp-in/limp-home” mode even with a cam sensor signal problem. Other possible symptoms include:
Causes
A code P0346 may indicate one or more of the following:
Possible Solutions
It is recommended to start by searching for a technical service bulletin (TSB) specific to the vehicle. The vehicle manufacturer may have a PCM flash/reprogram to address this issue, so it is worth checking before pursuing other avenues. One known service bulletin involves recalibrating the PCM (bulletin # EG010-05).
Replacing the camshaft position sensor often resolves this code, but not always. Therefore, it is important to perform the following checks:
Related Camshaft Trouble Codes: P0340, P0341, P0342, P0343, P0345, P0347, P0348, P0349, P0365, P0366, P0367, P0368, P0369, P0390, P0391, P0392, P0393, P0394.
