Camshaft Position Sensor
The Camshaft Position (CMP) sensor is located on the front face of the bank two cylinder head. The sensor tip protrudes through an aperture in the front face of the cylinder head to pick up on a reluctor ring behind the camshaft pulley.
The CMP sensor is a Hall effect sensor which is used by the Powertrain Control Module (PCM) at engine start-up to synchronize the PCM with the Crankshaft Position (CKP) sensor signal. The PCM does this by using the CMP sensor signal to identify the stroke of the piston in number one cylinder to ensure the correct injector timing. Once the PCM has established the injector timing, the CMP sensor signal is no longer used.
The CMP sensor receives a 5 V supply from the PCM. Two further connections to the PCM provide ground and signal output.
If a fault occurs, an error is registered in the PCM.
Two types of failure can occur:
- No CMP sensor signal
- A synchronization error of the CMP and CKP sensors.
The error recorded by the PCM can also relate to a total failure of the crankshaft signal or crankshaft signal dynamically implausible. Both components should be checked to determine the cause of the fault.
If a fault occurs with the CMP sensor when the engine is running, the engine will continue to run but the PCM will deactivate charge air pressure control. Once the engine is switched off, the engine will crank but will not restart while the fault is present.