EGR Valve
1. Engine operating at normal temperature 60°C (120°F).Comp. Loc:
WARNING: If EGR valve is hot, it may be necessary to wear gloves to avoid burning fingers.
Movement Of EGR Valve Diaphragm:
2. Place finger on EGR valve diaphragm and accelerate engine; diaphragm should move.
3. Disconnect vacuum hose from EGR valve.
4. Apply 10 inches of vacuum using a vacuum pump to valve with finger on diaphragm. It should move and engine may stall.
5. Check for carbon in valve which may cause restriction. Restriction may be small enough so that engine may stall during step 4, but large enough to cause a Code 51 to set. If valve passes the above test check EGR modulator. If valve fails, replace valve.