Exhaust Gas Recirculation: Testing and Inspection

1. INSPECT AND CLEAN FILTER IN EGR VACUUM MODULATOR.





- Remove the cap and filter.
- Check the filter for contamination or damage.
- Using compressed air, clean the filter.
- 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.
- Start the engine and check that the engine starts and runs at idle.
4. CONNECT TOYOTA HAND-HELD TESTER OR OBD II SCAN TOOL.





- Connect the TOYOTA hand-held tester or OBD II scan tool to the DLC3.
- Please refer to the TOYOTA hand-held tester or OBD II scan tool operators manual for further details.
5. INSPECT VSV OPERATION WITH COLD ENGINE.
- The engine coolant temperature should be below 50°C (122°F).
- Check that the vacuum gauge indicates zero at 3,000 rpm.
- Check that the EGR pipe is not hot.
6. INSPECT OPERATION OF VSV AND EGR VACUUM MODULATOR.
- Select the active test mode on the TOYOTA hand- held tester (VSV is closed.).
- If you have no TOYOTA hand-held tester, check these procedures:





- Remove the 3-way connector with the vacuum hose.
- Connect the vacuum hose (from port Q of EGR vacuum modulator) to the EGR valve.
- Plug the vacuum hose (from VSV for EGR).
- Check that the vacuum gauge indicates low vacuum at 3,000 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.





- Apply vacuum directly to the EGR valve with the engine idling.
- Check that the engine runs rough or dies.
- Reconnect the vacuum hoses to the proper locations. IF NO PROBLEM IS FOUND WITH THIS INSPECTION, SYSTEM IS NORMAL; OTHERWISE INSPECT EACH PART.