| Description and Operation General The engine management system of the 1.3 litre Endura-E engine consists of a powertrain control module and a number of sensors or actuators. The sensors supply the powertrain control module with input signals which relate to engine operating conditions and the actuators respond to output signals from the powertrain control module. These output signals are based on the evaluated input signals which are compared with calibrated data tables or maps before the output signal is generated. The 1.3 litre Endura-E engine meets 96 EEC emission regulations. To achieve this standard of emission control, the engine is equipped with a catalytic converter and an evaporative emission fuel vapour management system. Engine management system diagnosis may be carried out using FDS 2000 connected to the vehicle via the data link connector located in the passenger cowl side trim panel. Powertrain Control Module The engine management system utilises a powertrain control module (EEC V) which is located behind the passenger cowl side trim panel. The powertrain control module is protected by a steel security cover to maintain the integrity of the passive anti-theft system. The security cover is retained by three steel rivets. Evaporative Emission System The evaporative emission fuel vapour management system consists of a carbon canister and a purge valve. A combination of plastic, rubber and steel pipes connect the fuel tank, the carbon canister, the purge valve and the inlet manifold. When the purge valve is closed, the fuel tank is vented into the carbon canister which absorbs the fuel vapour and prevents the release of hydro-carbons into the atmosphere. When the purge valve is activated, the carbon canister is exposed to inlet manifold vacuum and the fuel vapour deposits are drawn into the inlet manifold where they mix with the incoming air/fuel charge. The evaporative emission fuel vapour management system is controlled by the powertrain control module according to calibrated data tables. The function of the system is to reduce hydro-carbon emissions from the fuel tank. Throttle Position Sensor The throttle position sensor is a rotary potentiometer which is secured to the throttle body and operated by the throttle plate spindle. The throttle position sensor is supplied with a reference voltage by the powertrain control module. When the throttle plate is opened, a sliding contact moves over a resistance track, changing the output voltage. The output voltage is assigned to a corresponding throttle plate position by the powertrain control module. Idle Air Control Valve The idle air control valve is an electronically controlled solenoid valve which allows a flow of air to bypass the throttle plate. Engine idle speed can therefore be maintained irrespective of engine load. The idle air control valve is controlled by grounding pulses from the powertrain control module. The length of the pulse determines the position of the valve. Camshaft Position Sensor The camshaft position sensor is an inductive pulse generator which scans a reference cam on the camshaft. The camshaft position sensor sends an alternating voltage signal to the powertrain control module. From this signal the firing position of number one cylinder is calculated. This is only required during starting. When the engine is running, the profile ignition pick-up (PIP) signal is used to sequentially control the fuel injectors. Mass Air Flow Sensor (Fitted Up to 99 MY) The mass air flow sensor measures the mass of air entering the intake system, the measurement being based on the constant temperature hot wire principle. Suspended in a bypass duct are a hot wire probe and an air temperature probe. The powertrain control module ensures that the hot wire is always 200° C hotter than the air temperature probe. The hot wire probe is cooled by the air flowing through the intake system and the powertrain control module varies the heating current to maintain the 200° C temperature difference. The change in the heating current is measured as a voltage drop across a precision resistor and is assigned to a corresponding mass air flow calculation by the powertrain control module. Crankshaft Position Sensor The crankshaft position sensor is an inductive pulse generator which scans 36 minus 1 cast protrusions on the flywheel. Minus one means that one of the protrusions is missing. This missing protrusion is located at 90° before top dead centre and is used by the powertrain control module as a reference mark for the crankshaft position. The crankshaft position sensor sends an alternating voltage signal to the powertrain control module, which is used to determine engine speed and ignition timing. Engine Coolant Temperature Sensor The engine coolant temperature sensor is a temperature dependant resister which has a negative temperature coefficient, i.e., its temperature changes inversely with respect to engine coolant temperature. The engine coolant temperature sensor is supplied with a reference voltage by the powertrain control module. When the engine coolant temperature changes, the resistance of the sensor changes thus changing the output voltage. The output voltage is assigned to a corresponding engine coolant temperature by the powertrain control module. Intake Air Temperature Sensor (Fitted Up to 99 MY) The intake air temperature sensor is a temperature dependant resistor which has a negative temperature coefficient, i.e., its temperature changes inversely with respect to ambient temperature. The intake air temperature sensor is supplied with a reference voltage by the powertrain control module. When the intake air temperature changes, the resistance of the sensor changes thus changing the output voltage. The output voltage is assigned to a corresponding intake air temperature by the powertrain control module. Heated Oxygen Sensor The heated oxygen sensor is a voltage generator which is installed ahead of the catalytic converter in the exhaust flow. When the air/fuel ratio is ideal (theoretically 14.7:1) or Lambda 1, a voltage signal of 450 mV is sent to the powertrain control module. When the mixture is lean, the voltage is reduced to 200 mV and the powertrain control module sets the air/fuel mixture towards rich. When the mixture is rich, the voltage signal is increased to 800m V and the powertrain control module sets the air/fuel mixture to lean. This provides control of exhaust emissions. To ensure the heated oxygen sensor quickly reaches its operating temperature of 300°C, it is equipped with a heating element which operates when the ignition is switched on. TMAP Sensor (Fitted 99 MY Onwards) The TMAP sensor is fitted directly into the inlet manifold and is therefore able to measure accurately the vacuum from the engine whilst it is running. The TMAP sensor consists of a pressure transducer and a temperature sensor and directly replaces the MAF and IAT sensors. The TMAP sensor provides the powertrain control module with information relating to inlet manifold vacuum and barometric pressure along with the temperature of the air within the inlet manifold. When the ignition is switched on with the engine off, the sensor reads barometric pressure and when the engine is running, the sensor reads inlet manifold vacuum. | 
