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Integrated Electronic EGR Valve

  1. Turn ignition off. Connect vacuum gauge to EGR valve. Apply vacuum and observe EGR valve. EGR valve should not move. If EGR valve moves, remove EGR filter and repeat test. EGR valve should not move. If valve moves, replace EGR valve. If valve does not move, replace filter.
  2. When applying vacuum, if EGR valve does not move, turn ignition on and repeat test. EGR valve should not move. If EGR valve moves, disconnect electrical connector.
  3. Connect 12-volt test light between terminals "A" and "D". Test light should not light. If test light does not light, EGR valve is faulty. If test light does light, circuit 435 is shorted to ground or ECM is faulty.
  4. With ignition on, ground diagnostic test terminal and repeat test. Valve should move. If valve does not move, remove EGR electrical connector. Connect test light between terminals "A" and "D".
  5. Test light should light. If test light does light, EGR valve or connection is faulty. If test light does not light, probe terminal "D" with test light to ground. Test light should light.
  6. If test light does light, circuit 435 or ECM is faulty. If test light did not light, circuit 39 is open. When diagnostic terminal was grounded, see if EGR valve moved. If so, disconnect vacuum hose at valve and connect vacuum gauge to hose.
  7. EGR valve should be able to obtain and hold 3-7 in. Hg vacuum. If valve holds vacuum above 7 in. Hg, remove EGR filter and repeat test. If vacuum is above 7 in. Hg, replace EGR valve. If vacuum was 3-7 in. Hg, replace EGR filter.
  8. If EGR valve is holding 3-7 in. Hg vacuum, start engine and lift EGR diaphragm. Idle should become rough. If idle does not become rough, remove EGR valve and clean passages. If idle did become rough, EGR valve is okay.
  9. Check for ported vacuum to EGR valve and check for leaks or restrictions in vacuum hoses. There should be at least 7 in. Hg vacuum at 2000 RPM. If further testing is required, see appropriate diagnostic chart in COMPUTER COMMAND CONTROL article.
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