EGR Valve: Description and Operation

EGR Valve Assembly Sectional View:

LINEAR EGR VALVE
LINEAR EGR CONTROL
The linear EGR valve is controlled by a high side driver within the PCM. The high side driver provides 12 volts that is pulse width modulated (PWM) by a duty cycle via the high control circuit of the EGR valve. The ground path is provided by the low control circuit of the EGR valve. The PCM calculates the amount of EGR needed based on the following inputs:
- The engine coolant temperature (ECT) sensor
- The intake air temperature (IAT) sensor
- The barometric pressure (BARO)
- The manifold absolute pressure (MAP) sensor
- The throttle position (TP) sensor
- The mass air flow (MAF) sensor