Circuit Description
WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
The DTC P0339 Crankshaft Position (CKP) Sensor Circuit Intermittent diagnostic verifies that the signal from the CKP sensor is continuous. The CKP sensor is a magnetic generator type sensor, producing an alternating current signal. The CKP sensor signal increases in both frequency and amplitude as the engine RPM increases. The CKP sensor sends this reference signal to the powertrain control module (PCM) to indicate the crankshaft RPM and position. This reference signal is used by the PCM to calculate fuel injection pulse, establish top dead center (TDC) for ignition timing and where to start ignition coil and injection sequencing. There will be no spark or fuel delivery if there is no CKP sensor signal.