Avalon & Camry 3.0L V6
The EGR system reduces oxides of nitrogen (NOx) emissions by lowering combustion temperatures. Combustion temperatures are lowered by recycling metered amount of exhaust gases back into the intake system.
The EGR system contains a vacuum-operated EGR valve, EGR Vacuum Control Valve (VCV), EGR position sensor and a vacuum tank. See Fig 1. An EGR gas temperature sensor is screwed into the lower side of EGR valve.
The EGR VCV regulates the intake manifold vacuum applied to the EGR Vacuum Switching Valve (VSV). The EGR operation is controlled by EGR VSV which is operated by the Engine Control Module (ECM). The EGR position sensor monitors movement of EGR valve and delivers an input signal to the ECM. The ECM uses this input signal to obtain the correct amount of EGR valve opening in relation to the engine operation. The ECM uses various input signals for controlling the EGR VSV. For EGR system and component testing, see SYSTEM/COMPONENT TESTS article.