EGR System Function Test

1. Run engine until operating temperature is reached.
2. Disconnect exhaust gas recirculation vacuum line from exhaust gas recirculation valve.
3. Ensure there is no vacuum from hose at idle, then raise engine speed to 2500 RPM, vacuum should exist.
4. Stop engine, then connect hand held vacuum pump to exhaust gas recirculation valve.
5. Apply vacuum and observe exhaust gas recirculation diaphragm movement. The diaphragm should move freely up and down.
6. Reconnect vacuum feed line. If exhaust gas recirculation valve does not operate as specified, check vacuum lines for kinks or physical damage.
7. If vacuum lines are satisfactory, replace exhaust gas recirculation valve.