1 Using TestBook/T4 clear the adaption values 2 Switch the ignition OFF for 10 seconds 3 Switch the ignition ON, for approximately 30 seconds the electric throttle control valve is briefly activated allowing the ECM to learn the new component. This procedure is also necessary after the ECM has been replaced. However the adaption values do not require clearing since they have not yet been established.
ENGINE MANAGEMENT SYSTEM – V 18-2-20 DESCRIPTION AND OPERATION Crankshaft Position (CKP) Sensor The CKP sensor is located in the lower right side of the transmission bell housing, inline with the engine flywheel. The sensor reacts to a reluctor ring to ascertain engine speed and position information. The sensor has three wires attached to it two signal wires and a sensor earth screen. The sensor earth screen is connected to chassis earth through the ECM. CKP Sensor The CKP sensor is an inductive type sensor which produces a sinusoidal output voltage signal. This voltage is induced by the proximity of the moving reluctor ring, which excites the magnetic flux around the tip of the sensor when each tooth passes. This output voltage will increase in magnitude and frequency as the engine speed rises and the speed at which the teeth on the reluctor ring pass the sensor increases. The signal voltage will peak at approximately 6.5 volts if connected to the ECM (further increases in engine speed will not result in greater magnitude. The ECM neither specifically monitors nor reacts to the output voltage (unless it is very small or very large, instead it measures the time intervals between each pulse (i.e. signal frequency. The signal is determined by the number of teeth passing the sensor, and the speed at which they pass. The reluctor ring has 58 teeth spaced at 6 ° intervals, with two teeth missing to give the ECM a synchronisation point. The signal produced by the CKP sensor is critical to engine running. There is no backup strategy for this sensor and failure of the signal will result in the engine stalling and/or failing to start. If the sensor fails when the engine is running, then the engine will stall, a fault code will be stored and details captured of the battery voltage, engine coolant temperature and intake air temperature at the time of the failure. If the signal fails when the engine is cranking, then the engine will not start and no fault will be stored, as the ECM will not detect that an attempt had been made to start the engine. In both cases the tachometer will also cease to function immediately and the MIL lamp will be permanently illuminated. During the power-down procedure, which occurs when the ignition is switched off, the ECM stores details of the position of the CKP and CMP sensors. This enables the ECM to operate the injectors in the correct sequence immediately the engine cranks, to produce a quick engine start, which serves to reduce emissions when the engine is cold.