The Camshaft Position Sensor (CMPS) is a sensor that detects the compression TDC of the NO. 1 cylinder. The CMPS consists of a hall type sensor and a target on the end of the intake camshaft. When the target triggers the sensor, the sensor voltage is 5V. If not, the sensor voltage is 0V. These CMPS signal is sent to the ECM and the ECM uses the CMPS signal for synchronizing the firing of sequential fuel injectors.
If there is no change of signal, the ECM judged as a fault and DTC is set.
Item
Detecting Condition
Possible Cause
DTC Strategy
? Change in output voltage(?Vcam) is monitored
? Poor connection
? Open or short in CMPS
? Defective CMPS
? Defective ECM
Enable Conditions
? Engine running condition
Threshold value
? ?Vcam = 0
Diagnostic Time
? Continuous
MIL ON condition
? 2 driving cycles
The given data is the normal waveform of the Crankshaft Position Sensor(CKPS) and Camshaft Position Sensor(CMPS) at idle. The ECM controls the injection timing and the 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.