The EGR (Exhaust Gas Recirculation) system is an emissions control system that takes some of the exhaust gases from your engine’s exhaust manifold and recirculates them back into the engine through the intake manifold. The exhaust gases are then drawn into the engine and combined with fresh air and fuel entering the cylinders. The system helps your engine to run more efficiently, consume less fuel, and put out fewer emissions.
At the heart of the emissions system is the EGR valve, and central to its operation is the EGR valve temperature sensor that lets the valve know when to open and close.
An EGR valve temperature sensor monitors the temperature of the gases flowing from the EGR valve during engine operation. The information it receives is sent to the engine’s computer, the ECM (Engine Control Module) where it is used to determine how much to open or close the EGR valve in order to produce the right amount of gas flow for a given condition.
The job of the EGR valve temperature sensor is to report the temperature of EGR system combustion gases back to the Engine Control Module to assist in determining the proper EGR gas flow rate at any given time or engine condition. These gases can be in the neighborhood of two thousand degrees Fahrenheit. They can also carry harsh chemicals that form a corrosive condensate on any and all EGR components.
If the EGR temperature sensor malfunctions due to electrical failure or contamination, you may notice one or more of the following symptoms: