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HOMESERVICE MANUALSFORD1987ECONOLINE E350, VAN DISPLAY EXTENDED, 6.9 1REPAIR AND DIAGNOSIS (SINGLE PAGE)ENGINE PERFORMANCESYSTEMCEC DIAGNOSING & TESTINGCIRCUIT TESTSTEST L - EGR VALVE POSITION (EVP) & EGR VALVE REGULATOR (EVR)
1987 Ford Econoline E350, Van Display Extended, 6.9 1

Test L - EGR Valve Position (EVP) & EGR Valve Regulator (EVR)

1987 Ford Econoline E350, Van Display Extended, 6.9 1SECTION Test L - EGR Valve Position (EVP) & EGR Valve Regulator (EVR)
  1. Code 31 Displayed. Turn key off. Disconnect EVP harness at sensor. Install a jumper wire between VREF and EVP signal at sensor harness connector. Perform KEY ON/ENGINE OFF SELF-TEST. Check for code 35. Ignore all other codes at this time. If code 35 is displayed, replace EVP sensor. Repeat QUICK TEST . If code 35 is not displayed, remove jumper wire and go to next step.
  2. With key off and EVP disconnected, set DVOM on 20-volt scale. Turn key on, leaving engine off. Measure voltage at EVP connector between VREF and signal return. If reading is less than 4.0 or more than 6.0 volts, go to TEST C - REFERENCE VOLTAGE , step 1). If reading is between 4.0 and 6.0 volts, go to next step.
  3. With key off, and EVP disconnected, set DVOM on 200-ohm scale. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, then connect ECA to box. Measure resistance between EVP signal at connector and test pin 27. If reading is 5 ohms or more, repair open circuit. Connect EVP sensor and remove breakout box. Repeat QUICK TEST . If reading is less than 5 ohms, go to next step.
  4. With key off and EVP harness disconnected, leave breakout box installed and ECA disconnected. Set DVOM on 200,000-ohm scale. Measure resistance between EVP signal at EVP connector and ground. Measure resistance between EVP signal at EVP connector and test pin 46. If either reading is less than 10,000 ohms, repair short circuit. Connect EVP and remove breakout box. Repeat QUICK TEST . If both readings are 10,000 ohms or more, replace ECA. Connect EVP and remove breakout box. Repeat QUICK TEST .
  5. Code 35 Displayed. Turn key off. Disconnect EVP harness at sensor. Inspect for and repair any damaged wiring. Perform KEY ON/ENGINE OFF SELF-TEST. Check for code 31. Ignore all other codes at this time. If code 31 is not displayed, go to step 7). If code 31 is displayed, go to next step.
  6. With key off and EVP harness disconnected, set DVOM on 20 volt scale. Turn key on, leaving engine off. Measure voltage at EVP harness connector between VREF and signal return. If reading is between 4.0 and 6.0 volts, replace EVP sensor. Repeat QUICK TEST . If reading is less than 4.0 volts or more than 6.0 volts, go to TEST C - REFERENCE VOLTAGE , step 1).
  7. Turn key off and disconnect EVP from harness. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM on 200,000 ohm scale. Measure resistance between test pin 27 and test pins 26 and 57. If either reading is less than 10,000 ohms, repair short in harness. Connect EVP sensor and remove breakout box. Repeat QUICK TEST . If both readings are 10,000 ohms or more, replace ECA. Connect EVP sensor and remove breakout box. Repeat QUICK TEST .
  8. Code 84 Displayed. Turn key off. Set DVOM on 200-ohm scale. Disconnect EVR solenoid connector and measure solenoid resistance. If reading is less than 30 ohms or more than 70 ohms, replace EVR solenoid assembly. Repeat QUICK TEST . If reading is between 30 and 70 ohms, go to next step.
  9. Leave EVR solenoid disconnected and set DVOM on 20-volt scale. Turn key on, leaving engine off. Measure voltage between negative battery terminal and VPWR circuit at solenoid harness connector. If reading is less than 10.5 volts, repair VPWR open circuit. Repeat QUICK TEST . If reading is 10.5 volts or higher, go to next step.
  10. With key off and EVR solenoid disconnected, disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box, leaving ECA disconnected. Set DVOM on 200-ohm scale. Measure resistance between test pin 33 and EVR signal at EVR solenoid connector. If reading is 5 ohms or higher, repair open circuit. Connect EVR solenoid and remove breakout box. Repeat QUICK TEST . If reading is less than 5 ohms, go to next step.
  11. With key off, breakout box installed, and ECA and EVR solenoid disconnected, set DVOM on 200,000-ohm scale. Measure resistance between test pin 33 and test pins 37, 57, 40, 46 and 60 (ground). If any reading is less than 10,000 ohms, repair short circuit. Remove breakout box, and connect ECA and EVR solenoid. Repeat QUICK TEST . If code is repeated, replace ECA. If all readings are 10,000 ohms or more, replace ECA. Remove breakout box, and connect ECA and EVR solenoid. Repeat QUICK TEST .
  12. Code 34 KEY ON/ENGINE OFF. Test indicates EGR valve and/or EVP sensor is not fully seated in closed position. Because of preload on installed EVP sensor, it is hard to determine whether EGR valve is not seated, or EVP sensor is not in contact with EGR valve stem. Turn key off, wait 10 seconds. Install known good EVP sensor on original EGR valve. Perform KEY ON/ENGINE OFF QUICK TEST . If code 34 is present, problem is with EGR and should be diagnosed. If code 34 is not present, original code 34 was because EVP sensor was defective. Service EVP sensor as necessary. Repeat QUICK TEST .
  13. Code 32 KEY ON/ENGINE OFF and ENGINE RUNNING SELF/TEST. Test indicates EGR valve and/or EVP sensor is lower than normal in closed position. Because of preload of EVP sensor is difficult to determine whether EGR valve is defective or if EVP sensor has extremely high resistance. Turn key off, wait 10 seconds. Install known good EVP sensor on original EGR valve. Perform KEY ON/ENGINE OFF QUICK TEST . If code 32 is present, problem is with EGR and should be diagnosed. If code 32 is not present, original code 32 was the result of original EVP sensor. Service as necessary. Repeat QUICK TEST .
  14. Code 33 on ENGINE RUNNING. Test indicates EVP sensor reading did not change after EVR solenoid was instructed by ECA to open EGR valve. EGR valve is electrically capable as indicated by a pass code 11 in KEY ON/ENGINE OFF SELF-TEST and/or EVP sensor is in expected closed EGR valve range. Turn key off. Using "T" install vacuum gauge at EGR valve. Perform Engine running QUICK TEST  while checking vacuum gauge. If vacuum gauge indicates 1.5 in Hg or greater vacuum, go to step 17). If vacuum gauge indicates less than 1.5 in. Hg of vacuum, go to next step.
  15. Turn key off. Disconnect vacuum source to EVR solenoid. Install vacuum gauge at vacuum line and start engine. If vacuum reading is 10 in. Hg or less, check vacuum line for cracks or damage. If vacuum reading is 10 in. Hg or more, go to next step.
  16. Carefully inspect vacuum line for cracks, loose connector, blockage, nicks and leaks. If vacuum line is good, check EGR solenoid filter for obstructions and replace as necessary. If filter is okay, replace EVR solenoid assembly and reconnect all vacuum lines. If vacuum lines are not good, service as necessary and repeat QUICK TEST .
  17. Turn key off, wait 10 seconds. Install known good EVP sensor on original EGR valve. Perform ENGINE RUNNING QUICK TEST . If code 33 is present, EGR valve is defective and must be diagnosed. If code 33 is not present, original code 33 was result of original EVP sensor. EVP sensor should be serviced as necessary and QUICK TEST  repeated.
  18. Turn key off. Remove vacuum hose from EGR valve and plug hose. Perform ENGINE RUNNING QUICK TEST . If code 34 is not present, inspect EVR filter for damage or obstructions and replace as necessary. If okay, replace solenoid assembly. Reconnect all vacuum lines and repeat QUICK TEST . If code 34 is present, go to next step.
  19. Turn key off. Remove harness from EVP sensor. Inspect for damaged pins, corrosion, and pins pushed out. Repair and replace as necessary. Set DVOM on 200,000-ohm scale. Remove vacuum line at EGR valve and connect vacuum pump. Measure resistance at EVP sensor between EVP signal and VREF while increasing vacuum to 10 in. Hg. Note resistance as vacuum increases. If resistance decreases gradually from no more than 5500 ohms to no less than 100 ohms, problem is with EGR and should be diagnosed. If resistance increases gradually, replace EVP sensor. ENGINE RUNNING SELF TEST code 38 indicates after operating EGR valve (during ENGINE RUNNING SELF-TEST) in EGR vacuum system was unable to maintain a specific (EVP) opening.
  20. Turn key off. Check vacuum line from EVR solenoid to EGR valve for any leakage. If vacuum line is good, replace EVR solenoid and repeat QUICK TEST . If vacuum lines are not good, replace and repeat QUICK TEST .
  21. Check Vacuum Line. Turn key off, wait 10 seconds. Be sure vacuum lines are reconnected. Check EGR vacuum line system from EGR valve for obstructions, kinks, leaks, etc. If lines are good, check EVR filter for obstructions. Replace as necessary. If okay, replace EVR solenoid. Reconnect all vacuum lines and repeat QUICK TEST . If vacuum lines are not in good condition, repair as necessary and repeat QUICK TEST .
  22. Code 32 CONTINUOUS Test. Code 32 indicates with engine at stabilized operating temperature and at idle, EVP circuit indicates that EGR valve is closed further than normal. Turn key off, wait 10 seconds. Remove 60 pin connector and inspect for damaged pins, corrosion or loose wires. Install breakout box and ECA. Connect vacuum pump to EGR valve. Connect DVOM from test pins No. 27 to 46. Set DVOM on 20-volt scale. Turn key on, leaving engine off. Watch DVOM and very slowly apply 6 in. Hg vacuum to EGR valve. Slowly bleed vacuum off EGR valve and lightly tap on EVP sensor. If there are no voltage readings less than .29 volts test is completed. If readings above .29 volts are indicated, EGR valve may have caused continuous code 32. Service to sensor is not required, but EGR valve service is indicated.
  23. Code 31 and/or Code 35 CONTINUOUS Test. Code 31 indicates, with engine at stabilized operating temperature and at idle, EVP circuit indicated an open or short to signal return Code 35 indicates, with engine at stabilized operating temperature and at idle, EVP circuit indicated a short to VREF and/or V power, or an open in signal return. Observe VOM or diagnostic tester for a fault while doing the following: wiggle, shake or bend a small section of the EEC IV harness closed to sensor connector. Check all wiring to dash panel. Also, wiggle and/or shake the EEC-IV harness from dash panel to ECA. If a fault is indicated, isolate and service as necessary. Repeat QUICK TEST . If fault is not indicated, go to next step.
  24. Turn key off, wait 10 seconds. Disconnect ECA 60 pin connector. Check both connectors for damage or faults. If connectors and terminals are okay, testing is complete. If not service and replace as necessary. Repeat QUICK TEST .
  25. Code 33 CONTINUOUS Test. Code 33 indicates, with engine at stabilized temperature and with a EVR solenoid duty cycle present, EGR valve did not open. Turn key off. Connect vacuum pump to EGR valve. If valve cannot maintain vacuum and stay open, valve may be defective and should be replaced. If it does stay open, go to next step.
  26. Use continuous monitor mode and observe VOM or diagnostic tester for a fault while wiggling and bending a small section of harness while working your way to ECA. Inspect connectors and terminals for faults. If any faults are indicated, isolate and repair as necessary. Repeat QUICK TEST . If fault is not indicated, testing is complete.
  27. Code 34 CONTINUOUS Test. Code 34 indicates, with engine at stabilized operating temperature and at idle, EGR valve is open. Turn key off. Disconnect harness from EVP sensor. Inspect for damaged pins, corrosion, etc. Set DVOM on 200,000-ohm scale. Disconnect vacuum line at EGR valve. Connect vacuum pump to EGR valve. Measure resistance at EVP sensor between EVP signal pin and VREF pin while increasing vacuum to 10 in. Hg. Observe resistance as vacuum increases. If reading does not decrease gradually, EGR valve is at fault and should be diagnosed. If reading gradually decreases from no more than 5500 ohms to no less than 100 ohms, go to next step.
  28. Turn key off. Remove vacuum hose from EGR valve and plug hose. Perform ENGINE RUNNING QUICK TEST . If code 34 is not present, you are unable to duplicate fault at this time. If code 34 is present, check EVR filter for obstructions and replace as necessary. If okay, replace EVR solenoid and reconnect vacuum lines. Repeat QUICK TEST .
Fig 1: EGR Valve Position (EVP) & EGR Valve Reg. (EVR) Circuits
G11083
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