Engine code PO340

P0340 - Camshaft Position Sensor Circuit Malfunction

There's only about a 50 percent chance the sensor named in a fault code is the cause of it. First we have to rule out wiring and connector terminal problems associated with that circuit.

By around the early 2000's, a lot of engines will run on just the crankshaft position sensor or the camshaft position sensor, in a back-up mode, but the engine has to be cranked long enough for the Engine Computer to figure out which pistons are coming up on top dead center, and which ones are on the compression stroke. That takes more crankshaft revolutions than normal before spark plugs and injectors start firing.

Normally in a case like this we would connect a scanner to see what the Engine Computer is seeing and responding to. That's about the only way to know if the camshaft position sensor's signal is showing up at the computer.