DTC P0340 Camshaft Position Sensor "A" Circuit (Bank 1 or Single Sensor): Description

The camshaft position sensor consists of a magnet and an iron core which is wrapped with copper wire, and is installed onto the cylinder head. When the camshaft rotates, each of 3 teeth on the camshaft passes through the camshaft position sensor. This activates the internal magnet in the sensor, generating a voltage in the copper wire. The camshaft rotation is synchronized with the crankshaft rotation. When the crankshaft turns twice, the voltage is generated 3 times in the camshaft position sensor. The generated voltage in the sensor acts as a signal, allowing the ECM to locate the camshaft position. This signal is then used to control ignition timing, fuel injection timing, and the VVT system.

HINT:

DTC P0340 indicates a malfunction relating to the camshaft position sensor circuit (the wire harness between the ECM and camshaft position sensor, and the camshaft position sensor itself).

Reference: Inspection using an oscilloscope

Fig 1: Identifying Waveform

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HINT:

• The correct waveform is as shown in the illustration.
• G2+ stands for the camshaft position sensor signal, and NE+ stands for the crankshaft position sensor signal.
• A failure of the ground for the shielding of the wiring may result in noisy waveforms.