Exhaust Gas Recirculation: Testing and Inspection

INSPECTION

1. INSPECT 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) Install 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
Start the engine and check that the engine starts and runs at idle.
4. CONNECT TOYOTA HAND-HELD TESTER OR OBD II SCAN TOOL





(a) Connect the TOYOTA hand-held tester or OBD II scan tool to the DLC3.
(b) Please refer to the TOYOTA hand-held tester or OBD II scan tool operators manual for further details.
5. INSPECT [1][2][3]VSV OPERATION WITH COLD ENGINE
(a) The engine coolant temperature should be below 50°C (122°F).
(b) Check that the vacuum gauge indicates zero at 3,500 rpm.
(c) Check that the EGR pipe is not hot.
6. INSPECT OPERATION OF [1][2][3]VSV AND EGR VACUUM MODULATOR
(a) Select the active test mode on the TOYOTA hand-held tester (VSV is closed.).





(b) If you have no TOYOTA hand-held tester, check these
procedures:
(1) Remove the 3-way connector with the vacuum hose.
(2) Connect the vacuum hose (from port Q of EGR vacuum modulator) to the EGR valve.
(3) Plug the vacuum hose (from VSV for EGR).
(c) Check that the vacuum gauge indicates low vacuum at 3,500 rpm.
7. DISCONNECT TOYOTA HAND-HELD TESTER OR OBD II SCAN TOOL
8. REMOVE VACUUM GAUGE
Remove the vacuum gauge and reconnect the vacuum hoses to the proper locations.





9. 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 the proper locations. If no problem is found with this inspection, system is normal; otherwise inspect each part.