What does P0340 camshaft position sensor A circuit bank 1 mean?
Short answer: The engine computer is not seeing a valid signal from the bank 1 camshaft position sensor, caused by a failed sensor, wiring or connector problems, or sometimes a timing or reluctor issue.
The camshaft position sensor tells the computer which stroke each cylinder is on so it can time injection and ignition. Without it, some engines still run using crank data, while others crank longer or will not start.
Check the scan tool for a cam signal and related codes, such as crank and cam correlation codes. Back-probe the sensor connector to check reference voltage, ground and signal. A scope shows whether the sensor produces a clean pattern while cranking or running.
If the sensor signal is missing even though power and ground are good, the sensor is suspect. If the signal is present but distorted, check for damaged reluctor teeth or a loose target wheel. Oil contamination in the connector is common on some engines. Keep hands, tools and test leads away from belts and pulleys while the engine is cranking or running.
Tools used for this job
General guidance only. Follow the vehicle and tool manufacturer's procedures, and confirm vehicle coverage on the tool maker's list before buying.