What is the EGR Control Solenoid all about?
Exhaust gas recirculation, or EGR, systems were developed to reduce engine emissions by reintroducing exhaust gas into the air/fuel mixture. This burns any remaining or partially burnt fuel in the exhaust and cools the combustion chamber, which produces fewer nitrous oxides. EGR systems have changed significantly, shifting from vacuum solenoid to electrically controlled systems. Modern EGR valves employ a solenoid that regulates the amount of exhaust that enters the intake process. Instead of being open and closed, the control solenoid ‘flutters’ rapidly, with the amount of open and closed times varying minutely with each flutter. When the engine temperature is cold, the EGR control solenoid allows little to no exhaust into the intake. While at wide open throttle, the solenoid is open nearly all the time.
When the EGR control solenoid doesn’t close during cold operation, the engine runs poorly or stalls. When the control solenoid doesn’t open properly, engine pinging or knocking is readily heard. In any situation of EGR control solenoid malfunction, the Check Engine light will come on.
Keep in mind:
- The EGR system operates at high temperatures. Don’t touch the EGR valve or other components until they have cooled off.
How it's done:
The EGR control solenoid is verified that it needs to be replaced. The engine trim cover is then removed for access.
The defective EGR control solenoid is disconnected from it's electrical connections and removed.
The new EGR control solenoid is installed and the electrical connections reconnected.
The engine is started and the EGR control solenoid is tested for operation. The engine trim panel is then reinstalled.
The vehicle is road tested to ensure proper operation of the EGR control solenoid.
The EGR control solenoid does not require maintenance or servicing. If the EGR control solenoid is found to be defective, it needs to be replaced by one of our expert technicians. It is also a good idea to check the solenoid’s operation when the EGR valve is being replaced.
What common symptoms indicate you may need to replace the EGR Control Solenoid?
- Engine runs rough or stalls at idle when cold
- Check Engine light comes on
- Engine pings or knocks when accelerating or under load
How important is this service?
The engine will not run well with an improperly operating EGR control solenoid. Your vehicle could fail an emissions or smog test if the control solenoid isn’t working. Have it replaced if it is deemed to be faulty.