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.
Checking oputput signals from CMP during engine running, if the expected number of cam tooth count is not observed, ECM sets P0391.
Item
Detecting Condition
Possible cause
DTC Strategy
Check if CAM sensor is synchronized correctly
Poor connection
Short in harness
electrical noise
Target wheel
CMPS(B2-Exhaust)
ECM
Enable Conditions
Engine running state
Threshold value
Cam tooth count ? 6
Diagnosis Time
Continuous
MIL On Condition
3 driving cycles
Specification
Output Voltage(V)
Hi : 5.0V
Low : 0.7V
Airgap(mm)
0.5 ~ 1.5
Fig.1) Normal waveforms of CMPS