Linear EGR Control
WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.
The linear EGR valve is controlled by a high side driver within the engine control module (ECM). 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 ECM 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