Exhaust Gas Recirculation (EGR) Cooler Bypass Valve Solenoid
The EGR cooler bypass valve solenoid is a PCM controlled vacuum solenoid. The EGR cooler bypass valve solenoid controls the EGR cooler bypass valve position by applying vacuum from the vacuum pump to the EGR cooler bypass valve actuator. The EGR cooler bypass valve solenoid is located at the top front of the EGR cooler.
When the EGR cooler bypass valve solenoid is commanded to 0% duty cycle by the powertrain control module (PCM), no vacuum from the vacuum pump is applied to the EGR cooler bypass valve actuator and the EGR cooler bypass valve is closed. When the EGR cooler bypass valve is closed, the exhaust gases pass through the EGR cooler to the intake manifold.
When the EGR cooler bypass valve solenoid is commanded to 100% duty cycle by the PCM, vacuum from the vacuum pump is applied to the EGR cooler bypass valve actuator and the EGR cooler bypass valve is opened. When the EGR cooler bypass valve is open, the exhaust gases pass directly to the intake manifold without passing through the EGR cooler.