Camshaft Position Sensor (CMPS) is a hall sensor and detects the camshaft position by using a hall element. It is related with Crankshaft Position Sensor (CKPS) and detects the piston position of the each cylinder which the CKPS can’t detect. The CMPS are installed on engine head cover and uses a target wheel installed on the camshaft. This sensor has a hall-effect IC which output voltage changes when magnetic field is made on the IC with current flow. When teeth on the target wheel trigger the sensor, output voltage is 12V. If not, it is 0V. These CMP signal is sent to the PCM and used for determining the ignition timing along with CKP signal. CMPS makes Sequential Injection possible.
If the signal input is low with no phase edge, PCM sets DTC P0342.
Item
Detecting Condition
Possible Cause
DTC Strategy
Signal check, Low
Poor connection
Short to ground in signal circuit
CMPS
Enable Conditions
Signal low and no phase edge
Threshold Value
No phase edge detected
Diagnostic Time
Continuous
MIL ON Condition
3 driving cycle
This example shows a typical Crankshaft Position Sensor(CkPS) and Camshaft Position Sensor(CMPS) waveform at idle. The PCM controls the injection and ignition timing by using these signals. Generally CkPS signal is used to detect the piston’s position and CMPS signal is used to detect the Top Dead Center of each cylinder.