Circuit Description

WARNING: This page is about a different car, the 2003 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.

Exhaust Gas Recirculation (EGR) system recirculates exhaust gases to reduce combustion temperatures and exhaust emissions. The amount of exhaust gases that EGR valve recirculates is controlled by EGR vacuum modulator according to engine load. If even one of the following conditions is fulfilled, the VSV is turned ON by a signal from the ECM. This results in atmospheric air acting on the EGR valve, closing the EGR valve and shutting off the exhaust gas flow (EGR cut-off). Under the following conditions, EGR is cut to maintain driveability:

Before the engine is warmed up.
During deceleration (throttle valve closed).
Light engine load (amount of intake air very small).
Engine racing.