Exhaust Gas Recirculation: Testing and Inspection
SYSTEM INSPECTIONFig. 144 EGR Valve:
NOTE: Check condition of wiring harness and/or vacuum lines and connectors before checking sensors or switches.
1. Start engine.
2. Accelerate and check that EGR valve diaphragm does not move while engine is still cold.
3. Warm engine to operating temperature and run at idle.
WARNING: Use care when checking. Surrounding area is hot.
4. Accelerate and check that EGR valve diaphragm moves upward.
SOLENOID VALVE (EGR, VACUUM SIDE)
Testing EGR Vacuum Solenoid:
1. Disconnect vacuum hoses.
2. Blow through hose and make sure air does not flow.
3. Disconnect valve connector.
4. Apply 12V and ground to valve as shown.
5. Blow through hose and make sure air flows.
6. If not correct, replace valve.
SOLENOID VALVE (EGR, VENT SIDE)
Testing EGR Vent Solenoid:
1. Disconnect hoses.
2. Blow through hose and make sure air flows.
3. Disconnect valve connector.
4. Apply 12V and ground to as shown.
5. Blow through vacuum hose and make sure air does not flow.
6. If not correct, replace valve.
EGR CONTROL VALVE
Checking EGR Valve:
1. Check that valve rod slides smoothly by a hand.
2. Disconnect vacuum hose and connect vacuum pump to valve.
3. Start engine, run at idle, and apply vacuum.
4. Check that engine runs roughly or stalls at more than 1.6 - 2.4 inHg (40 - 60 mmHg) of applied vacuum.
5. If not correct, remove EGR valve and check for carbon plugging passages. If not plugged, replace valve.