The intake throttle body is mounted on the lower intake manifold. The intake throttle body promotes flow of EGR gases to the intake manifold by creating a differential between exhaust pressure and intake pressure.
ECT2 monitors secondary cooling system temperature, which affects EGR cooler temperature and performance.
The EGR cooler bypass valve alters the flow of EGR gases to increase the temperature of the gas at low engine speeds. The vacuum controlled valve is solenoid controlled by the PCM. If the PCM determines that it does not need to cool the exhaust gas,it commands the EGR solenoid to close the bypass valve… Read More »
During some operating conditions the EGR cooler is bypassed.
The exhaust gas enters through the EGR valve and then goes through the EGR bypass valve. As the exhaust gas enters the EGR cooler, it is first cooled by the primary cooling system. It flows through the secondary EGR cooler where it is cooled further before exiting the EGR cooler and entering the intake air… Read More »
The second part of the EGR cooler is cooled by the powertrain secondary cooling system. An internal air-to-coolant heat exchanger absorbs heat from the exhaust gases and dissipates heat to the atmosphere through the powertrain secondary radiators.
The first part of the EGR cooler is cooled by the primary cooling system. An internal air-to-coolant heat exchanger absorbs heat from the exhaust gases and dissipates heat to the atmosphere through the primary radiators.
The EGR system uses an EGR cooler after the EGR valve. This keeps the EGR valve cleaner than previous engines. The EGR cooler is located on the right valve cover, for easier service. The cooler EGR temperature reduces NOx emissions.
The EGR valve receives a duty cycle signal from the PCM and sends a variable voltage signal from the Exhaust Gas Recirculation Valve Position (EGRVP) sensor back to the PCM to indicate actual position. Internally, it has two valves connected by a common shaft. Exhaust gases are routed from the right exhaust manifold to the… Read More »
The EGR system allows cooled (inert) exhaust gases to re-enter the combustion chamber, which lowers combustion temperatures and Oxides of Nitrogen (NOx) emissions. EGR system control is based off an air system model to estimate the percentage of exhaust gas in the cylinder. The PCM looks at engine temperature, intake pressure, exhaust pressure (EP), RPM,… Read More »