ZEST BOLT Service Manual

ENGINE 1.3 QUADRAJET (75PS) 86 1. Connection lead 2. Protective sleeve 3. Planar sensor element 4. Ceramic support pipe 5. Sensor seat 6. Ceramic seal 7, Protective pipe ELECTRICAL SPECIFICATIONS: Q Max 7.5 V heater power supply from control unit Q Heater resistance 3.2 ± 0.8 Ù PIN OUT 1. Pumping current (lp) 2. Virtual mass 3. Heater (-) 4. Heater (+) 5. Calibration current 6. Nerst voltage C. EXHAUST GAS RECIRCULATION (EGR). This system makes it possible to send some (5 - 15%) of the exhaust gases to the inat ke in certain operating conditions. This lowers the peak temperature in the combustion chamber restricting the formation of nitrogen oxides (NOx). The E.G.R. solenoid valve (1) operated by the injection control unit (2) carries out the t ask of reintroducing some of the exhaust gases t aken from the exhaust manifold (4) back into the engine intake. A heat exchanger (3) allows the partial cooling of the exhaust gases further lowering the temperature of the combustion chamber. 1 - EGR solenoid 2 - Injection control unit 3 - Heat exchanger 4 - Exhaust manifold 5 - Air intake manifold WORKING At coolant temperatures of > 20°C with the engine speed between 800 and 3000 rpm, the injection control unit operates the E.G.R. solenoid valve with a square wave signal. The variation in this signal allows the E.G.R. coil to move a shutter, thereby regulating the flow of exhaust gases from the exhaust manifold to the int ake manifold; there are two results: