Exhaust Gas Recirculation (EGR) Valve

The EGR valve is located on the side of the cylinder head near the upper radiator hose. Exhaust gas is introduced into the intake manifold via the EGR valve to be mixed with the air/fuel during combustion. EGR is used to cool combustion chamber temperatures which reduce Oxides Of Nitrogen (NOx), an emission gas related to combustion temperatures. The EGR valve consists of a pintle valve that moves by the use of an Internal solenoid and an internal position sensor (potentiometer) used to determine pintle valve position. The PCM controls the solenoid by supplying ignition voltage whenever exhaust gas needs to be recirculated into the intake manifold. The position sensor works exactly like that of a TP sensor. The PCM supplies the sensor 5 volts and a ground. A sweep arm is used to give the signal voltage level at a certain position of the valve.