Tacoma 2.7L 4-Cyl. 3RZ-FE

WARNING: This page does not describe the selected car, but rather 16 other vehicles, including the 2002 Toyota Tundra, 2002 Toyota Tacoma, 2002 Toyota Sienna, 2002 Toyota Sequoia, and 2002 Toyota RAV4. However, it is still accessible from the selected car via links, so may be relevant.

Exhaust Gas Recirculation (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 intake system. EGR system contains a vacuum-operated EGR valve, EGR vacuum modulator and EGR Vacuum Switching Valve (VSV). See Fig 1. Amount of EGR operation is regulated by EGR vacuum modulator according to engine load. EGR valve operation is controlled by EGR VSV which is controlled by Engine Control Module (ECM). If ECM turns on EGR VSV, this causes EGR valve to close and shut off the exhaust gas. ECM may shut off EGR system if any of the following conditions exist:

Engine Is Not At Normal Operating Temperature
During Deceleration With Throttle Closed
During Light Engine Load
Engine Is At High Speed

The ECM uses various input signals for controlling EGR system operation. For EGR system and component testing, see EXHAUST GAS RECIRCULATION SYSTEM under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING - 4-CYLINDER article.

Fig 1: Identifying EGR System Components (Tacoma 2.7L 4-Cyl. 3RZ-FE)