Exhaust Gas Recirculation: Testing and Inspection

EGR SYSTEM INSPECTION

1. CHECK AND CLEAN FILTER IN EGR VACUUM MODULATOR





(a) Remove the cap and filter.
(b) Check the filter for contamination or damage.
(c) Using compressed air, clean the filter.
(d) Reinstall the filter and cap.

HINT: Install the filter with the coarser surface facing the atmospheric side outward.





2. INSTALL VACUUM GAUGE
Using a 3-way connector, connect a vacuum gauge to the hose between the EGR valve and EGR vacuum modulator.
3. INSPECT SEATING OF EGR VALVE
Check that the engine starts and runs at idle.
4. INSPECT VSV OPERATION WITH COLD ENGINE
(a) The engine coolant temperature should be below 45°C (113°F).
(b) Chock the 4 wheels.
(c) Fully apply the parking brake.





(d) Connect the LEXUS hand-held tester or OBD II scan tool the DLC3.
(e) Start the engine and check idle.
(f) Keep your foot pressed firmly on the brake pedal.
(g) Shift into the D position. Press the accelerator pedal slowly and hold the engine speed at 1,200 - 1,600 rpm.
(h) Check that the vacuum gauge indicates zero.
5. INSPECT OPERATION OF VSV AND EGR VACUUM MODULATOR WITH HOT ENGINE
(a) Warm up the engine to above 50°C (122°F).
(b) Chock the 4 wheels.
(c) Fully apply the parking brake.
(d) Connect the LEXUS hand-held tester or 0BDII scan tool the DLC3.
(e) Start the engine and check idle.
(f) Keep your foot pressed firmly on the brake pedal.
(g) Shift into the D position. Press the accelerator pedal slowly and hold the engine speed at 1,200 - 1,600 rpm.
(h) Check that the vacuum gauge indicates low vacuum.
6. REMOVE VACUUM GAUGE
Remove the vacuum gauge and reconnect the vacuum hoses to their proper locations.





7. INSPECT EGR VALVE
(a) Apply vacuum directly to the EGR valve with the engine idling.
(b) Check that the engine runs rough or dies.
(c) Reconnect the vacuum hoses to their proper locations.
IF NO PROBLEM IS FOUND DURING THIS INSPECTION, SYSTEM IS NORMAL; OTHERWISE INSPECT EACH PART