LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 1995 >> Avalon XL >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Emission Systems & Sub-Systems >> Exhaust Gas RECIRCULATION System Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Exhaust Gas RECIRCULATION System Test

NOTE: Exhaust Gas Recirculation (EGR) systems contain different components depending on application. See Fig 2 or Fig 3 . When testing EGR system and components, use proper illustration to determine component location.
NOTE: When performing EGR system test, it will be necessary to monitor engine RPM by using tachometer or scan tester depending on model application. For tachometer or scan tester connections, see IDLE SPEED & MIXTURE in ADJUSTMENTS article.
  1. Ensure EGR vacuum modulator filter is clean and in good condition. Clean filter with compressed air (if necessary).
    NOTE: EGR vacuum modulator filter must be installed with coarse side facing upward, away from EGR vacuum modulator.
  2. Using "T" connector, install vacuum gauge in line with vacuum hose on top of EGR valve. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve.
  3. Install Jumper Wire (SST 09843-18020) between terminals "TE1" and "E1" of DLC-1 located in engine compartment. See Figure.
    NOTE: The EGR system components can be checked with engine coolant temperature less than minimum temperature and engine at specified engine RPM.
  4. Operate engine with engine coolant temperature less than minimum temperature and at specified RPM. See EGR TESTING SPECIFICATIONS  table. No vacuum reading should be obtained.
  5. Warm engine to normal operating temperature. Operate engine at specified engine RPM again. See EGR TESTING SPECIFICATIONS  table. Ensure a low vacuum reading is now obtained.
  6. Disconnect vacuum hose from port "R" of EGR vacuum modulator. See Fig 1. Using additional hose, connect port "R" of EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See EGR TESTING SPECIFICATIONS  table.
    NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
  7. Remove vacuum hose, vacuum gauge and reconnect original vacuum hoses. To check EGR valve operation, remove and plug vacuum hose located on top of EGR valve.
  8. Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested. Shut engine off. Remove jumper wire from DLC-1.
Fig 1: Identifying Ports & Testing EGR Vacuum Modulator
G95A34439Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
EGR TESTING SPECIFICATIONS

Application Minimum Temperature Engine RPM
Avalon 131°F (55°C) (1) 2800
(1) Check at 3500 RPM when applying vacuum to port "R" on EGR vacuum modulator.
Fig 2: Identifying Emission System Components (California)
G95D34440Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Fig 3: Identifying Emission System Components (Except California)
G95E34441Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
scientia non olet · About LEMON Manuals