Camshaft Position (CMP) Sensor The CMP sensor is located in a hole in the top of the camshaft cover. The sensor is sealed in the cover with an O- ring seal and secured with a screw. The sensor tip is aligned with a target which is integral with the inlet camshaft. The target design produces one square wave signal pulse for every full rotation of the camshaft. The ECM uses the CMP sensor signal to determine if the piston in No. 1 cylinder is at injection TDC or exhaust TDC. Once this has been established, the ECM can then operate the correct injector to inject fuel into the cylinder when the piston is at injection TDC. The CMP sensor is a Hall effect sensor which used by the ECM at engine start-up to synchronise the ECM with the CKP sensor signal. The ECM does this by using the CMP sensor signal to identify number one cylinder to ensure the correct injector timing. Once the ECM has established the injector timing, the CMP sensor signal is no longer used.
ENGINE MANAGEMENT SYSTEM – TD 18-1-30 DESCRIPTION AND OPERATION The CMP sensor receives a V supply from the ECM. Two further connections to the ECM provide ground and signal output. If a fault occurs, an error is registered in the ECM. Two types of failure can occur camshaft signal frequency too high or total failure of the camshaft signal. The error recorded by the ECM 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 ECM will deactivate boost pressure control. Once the engine is switched off, the engine will crank but will not restart while the fault is present. Fuel Injector There are six electronic fuel injectors (one for each cylinder) located in a central position between the four valves of each cylinder. The ECM divides the injectors into two banks of three with cylinders 1 to 3 being designated bank 1 and cylinders 4 to 6 designated bank 2. +