The Camshaft Position (CMP) 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 CMP 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 CMP 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.


DTC Detection Condition

Trouble Area

• No Camshaft Position (CMP) sensor signal to ECM while cranking (2 trip detection logic)

Case 2

• Camshaft/Crankshaft misalignment detected at engine speed of 600 rpm or more (1 trip detection logic)

• Open or short in CMP sensor circuit

• Jumped tooth of timing chain

DTC P0340 indicates a malfunction relating to the CMP sensor (+) circuit (the wire harness between the ECM and CMP sensor, and the CMP sensor itself). Reference: Inspection using an oscilloscope

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• The correct waveform is as shown in the illustration.

• G2+ stands for the CMP sensor signal, and NE+ stands for the Crankshaft Position (CKP) sensor signal.

• Grounding failure of the shielded wire may cause noise in waveforms.




CHI: G2+ - G2-CH2: NE+ - NE-

Equipment Settings

5 V/Division, 20 ms./Division


Cranking or idling

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