Technical Description of OBD-II Trouble Code
The circuit for Camshaft Position Sensor “A” is registering a low voltage (Bank 1)
What does that signify?
This is a generic diagnostic trouble code (DTC) for the powertrain, which applies to all makes and models from 1996 onwards. However, the specific steps for troubleshooting will vary depending on the vehicle.
The automotive trouble code P0342 is one of several generic malfunction codes related to the camshaft position sensor (CPS). Trouble codes P0335 through P0349 are all generic codes that pertain to the CPS and indicate different reasons for the failure.
In this case, code P0342 indicates that the sensor’s signal is too low or not strong enough. The signal is too weak to be clear and difficult to interpret. P0342 refers to the Bank 1 “A” sensor, which is located on the side of the engine that contains cylinder #1.
Description and correlation of the crankshaft and camshaft position sensors
It is important to understand what these sensors are and how they interact in today’s vehicles. All distributorless ignition vehicles use a crank and cam sensor instead of the module and trigger wheel found in an electronic distributor.
The crankshaft position sensor (CPS) informs the engine control module about the position of the pistons relative to top dead center, which helps in injecting fuel and firing the spark plugs.
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
The crank and cam sensors provide an “on and off” signal. Both sensors function using either hall effect or magnetic technology.
A hall effect sensor utilizes an electro-magnetic sensor and a reluctor. The reluctor is shaped like small cups with squares cut out of the sides, resembling a picket fence. The reluctor spins while the sensor remains stationary and mounted very close to the reluctor. Every time a post passes in front of the sensor, a signal is produced, and when the post passes, the signal turns off.
A magnetic pickup uses a stationary sensor and a magnet attached to the rotating part. Every time the magnet passes in front of the sensor, a signal is produced.
Locations
A hall effect crank sensor is located on the harmonic balancer at the front of the engine. The magnetic pickup can be found on the side of the engine block, where it uses the center of the crankshaft for a signal, or it can be located in the bellhousing, where it uses the flywheel as a trigger.
The camshaft sensor is mounted either at the front or rear of the camshaft.
Note: In the case of GM vehicles, the code description is slightly different, indicating CMP Sensor Circuit Low Input Conditions.
Symptoms
The symptoms may include:
Potential Causes
The potential causes for this DTC may include:
Diagnostic and Repair Procedures
Check the technical service bulletins (TSBs) for any that are relevant to this code. TSBs provide a list of complaints and failures addressed at the dealer level, along with the recommended solutions by the manufacturers.
Example photo of a camshaft position sensor (CMP):
Related Camshaft Trouble Codes: P0340, P0341, P0343, P0345, P0346, P0347, P0348, P0349, P0365, P0366, P0367, P0368, P0369, P0390, P0391, P0392, P0393, P0394.
