What does it mean?
This is a generic powertrain diagnostic trouble code (DTC), meaning it covers all makes/models from 1996 onward. However, specific troubleshooting steps vary by vehicle.
The P0347 automotive fault code is one of many generic malfunction codes related to the camshaft position sensor (CPS). Fault codes P0335 through P0349 are all generic CPS-related codes indicating different failure reasons.
In this case, code P0347 indicates the sensor signal is too weak or not strong enough. The signal is weak enough to be vague and difficult to interpret. P0347 refers to Bank 2 Sensor “A”. Bank 2 is the engine side that does not contain cylinder #1.
Description and correlation of crankshaft and camshaft position sensors
It’s important in today’s vehicles to understand what these sensors are and how they interact. All distributorless ignition vehicles use crank and cam sensors to replace the module and trigger wheel found in an electronic distributor.
The crankshaft position sensor (CPS) signals the engine control module the location of pistons relative to top dead center in preparation for fuel injection and spark plug firing.
The camshaft position sensor (CMP) signals the position of the camshaft intake lobe relative to the CPS signal and the opening of the intake valve for fuel injection on each cylinder.
Description and location of sensors
Crank and cam sensors provide an “on/off” signal. Both are either Hall effect or magnetic.
A Hall effect sensor uses an electromagnetic sensor and a reluctor. The reluctor is shaped like small cups with squares cut out on the sides, making it look like a fence. The reluctor rotates while the sensor is stationary and mounted very close to the reluctor. Whenever a post passes by the sensor, a signal is produced, and when the post passes, the signal turns off.
A magnetic sensor uses a fixed sensor and a magnet attached to the rotating part. Whenever the magnet passes by 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 sensor may be located on the side of the engine block where it uses the center of the crankshaft for a signal, or it may be in the housing where it uses the flywheel as a trigger.
The camshaft sensor mounts at the front or rear of the camshaft.
Symptoms
Symptoms may include:
- Check engine light (malfunction indicator) illuminated with P0347 code set
- Lack of power
- Stumbling
- Hard starting
Potential Causes
Causes of this DTC may include:
- Faulty camshaft position sensor
- Sensor harness open or shorted
- Poor electrical connections
- Faulty starter
- Bad wiring to starter
- Poor battery
Diagnostic and Repair Procedures
Check technical service bulletins (TSBs) for anything related to this code. TSBs are a list of complaints and failures handled at the dealership level and the fixes recommended by manufacturers.
- Check battery condition. A weak battery can cause the code to set.
- Check all starter wiring. Look for corrosion, loose connections, or frayed insulation.
- Check connector on camshaft sensor. Look for corrosion and bent pins. Apply dielectric grease to pins.
- Check starter for excessive draw indicating a weak starter.
- Replace camshaft position sensor.
Example photo of a camshaft position sensor (CMP):
