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Test M - EVP & EVR4

  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 (KOEO) 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 No. 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 No. 46. If either reading is less than 10,000 ohms, repair short circuit. Connect EVP and remove breakout box. Repeat QUICK TEST  . If both reading 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 KOEO 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 No. 27 and test pins No. 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 No. 33 (52 on 2.3L HSC/CFI engine) and EVR signal at EVR solenoid connector. If reading is 5 ohms or more, 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 No. 33 (52 on 2.3L HSC/CFI engine) and test pins No. 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. Key On/Engine Off Self-Test Code 34 Displayed. Turn key off and wait 10 seconds. Install a good known EVP sensor on original EGR valve. Perform KOEO SELF-TEST. If code 34 is present, check EGR valve for mechanical malfunction. If code 34 is not present, replace original EVP sensor. Repeat QUICK TEST  .
    NOTE: Code 34 indicates that the EGR valve and/or EVP sensor are not fully seated in the closed position. Preload on EVP sensor makes it difficult to determine whether EGR valve is not seated or if the EVP sensor is not in contact with EGR valve stem.
  13. KOEO Self-Test Code 32 Displayed. Turn key off and wait 10 seconds. Install a known good EVP sensor on original EGR valve. Perform KOEO SELF-TEST. If code 32 is present, check EGR valve for mechanical malfunction. If code 32 is not present, replace original EVP sensor. Repeat QUICK TEST  .
    NOTE: Code 32 indicates that EGR valve and/or EVP sensor is lower than normal in closed position. Preload on EVP sensor makes it difficult to determine whether the EGR valve has malfunctioned or if the EVP sensor has abnormally high resistance.
  14. KOER Self-Test Code 33 Displayed. Turn key off. Using vacuum "T", connect vacuum gauge at EGR valve. Perform KOER SELF-TEST and observe vacuum gauge. If reading is 1.5 in. Hg or greater, go to step 17). If reading is less than 1.5 in. Hg, go to next step.
  15. Turn key off. Disconnect vacuum source to EVR solenoid. Install vacuum gauge at source vacuum hose. Start engine. If reading is 10 in. Hg or greater, go to next step. If reading is less than 10 in. Hg, check vacuum hose to EVR solenoid. Replace if necessary. Repeat QUICK TEST  .
  16. Carefully check vacuum line for cracks, loose connections, blockage, kinks, and leaks. If vacuum hose is not okay, replace hose. Connect new vacuum hose and repeat QUICK TEST  . If vacuum hose is okay, check EVR solenoid filter for obstructions. Replace if necessary. If filter is okay, replace EVR solenoid. Connect all vacuum hoses and repeat QUICK TEST  .
  17. Turn key off. Wait 10 seconds. Install a good known EVP sensor on original EGR valve. Perform KOER SELF-TEST. If code 33 is present, check EGR valve and/or system for mechanical malfunction. If no code 33 is present, replace original EVP sensor. Repeat QUICK TEST  .
  18. KOER Self-Test Code 34 Displayed. Turn key off. Disconnect and plug EGR valve vacuum hose. Perform KOER SELF-TEST. If code 34 is not present, check EVR filter for obstructions. Replace if necessary. If filter is okay, replace EVR solenoid. Connect all vacuum hoses and repeat QUICK TEST  . If code 34 is present, go to next step.
  19. Turn key off. Disconnect harness from EVP sensor. Inspect connectors for damaged pins or corrosion. Repair if necessary. Set DVOM on 200,000-ohm scale. Disconnect vacuum hose to EGR valve and connect vacuum pump to valve. Measure resistance between EVP signal return and VREF while gradually increasing vacuum to 10 in. Hg. If reading decreases from no more than 5500 ohms to no less than 100 ohms, check EGR valve for mechanical malfunction. If reading does not change as indicated, replace EVP sensor. Reconnect vacuum hose.
  20. KOER Self-Test Code 38 Displayed. Turn key off. Disconnect vacuum hose at EGR valve and apply 10 in. Hg to EGR valve. If valve holds vacuum for 10 seconds, go to next step. If not, check EGR valve for mechanical malfunction. Code 38 indicates that EGR valve or EGR vacuum system was unable to maintain a specific opening.
  21. Turn key off. Closely inspect vacuum hose from EVR solenoid to EGR Valve for cracks, loose connections or damage. If hose is okay, replace EVR solenoid. Repeat QUICK TEST  . If hose is damaged, repair or replace as necessary. Repeat QUICK TEST  .
  22. Turn key off and wait 10 seconds. Ensure vacuum hoses are properly connected. Carefully check EGR vacuum hose for obstructions kinks, leaks, or damage. If hose is okay, check EVR filter for obstructions. Replace if necessary. If filter is okay, replace EVR solenoid. Connect vacuum hoses and repeat QUICK TEST  . If hose is damaged, replace hose and repeat QUICK TEST  .
  23. Continuous Code 32 Displayed. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect for and repair any damaged wiring. Install breakout box and connect ECA. Connect vacuum pump to EGR valve. Place DVOM on 20-volt scale and connect between test pins No. 27 and 46. Turn key on, leaving engine off. Observe DVOM readings.
  24. Slowly apply 6 in. Hg vacuum to EGR valve. Slowly bleed vacuum off EGR valve and lightly tap on EVP sensor to simulate road shock. If any readings are less than 0.29 volts, the EGR valve may have caused code 32. Check EGR valve for mechanical malfunction. If all readings are more than 0.29 volts, fault cannot be duplicated at this time. Test is completed.
  25. Continuous Code 31 or 35 Displayed. Using CONTINUOUS MONITOR (WIGGLE) TEST, observe VOM or diagnostic tester for fault indication while grasping harness close to sensor and wiggling, shaking, or bending a small section of EEC-IV harness while working toward firewall. Also wiggle, shake or bend harness from firewall to ECA. If fault is indicated, isolate fault and repair wiring harness as required. Repeat QUICK TEST  . If fault is not found, go to next step.
  26. Turn key off and wait 10 seconds. Disconnect ECA 60-pin connector. Inspect connector and terminals for obvious damage. If connector and terminals are damaged, repair as necessary. Repeat QUICK TEST  . If connector and terminals are okay, fault cannot be duplicated at this time. Test is completed.
  27. Continuous Code 33 Displayed. Turn key off. Connect vacuum pump to EGR valve. Apply 20 in. Hg to EGR valve. If EGR valve opens and holds vacuum, go to next step. If not, check EGR valve for mechanical malfunction.
  28. Using CONTINUOUS MONITOR (WIGGLE) TEST, observe VOM or diagnostic tester for fault indication. Grasp harness close to EVR solenoid connector and wiggle, shake, or bend a small section of harness while working toward ECA. Inspect connectors and terminals for obvious damage. If fault is indicated, isolate fault and repair as necessary. Repeat QUICK TEST  . If no fault is indicated, fault cannot be duplicated at this time. Testing is completed.
  29. Continuous Code 34 Displayed. Turn key off. Disconnect harness from EVP sensor. Inspect connector for obvious damage. Place DVOM on 200,000-ohm scale. Disconnect vacuum hose to EGR valve and connect vacuum pump to valve. Measure resistance at EVP sensor between test pins No. 26 and 27 while increasing vacuum to 10 in. Hg. If reading does not decrease gradually, check EGR valve for mechanical malfunction. If reading gradually decreases from no more than 5500 ohms to no less than 100 ohms, go to next step.
  30. Turn key off. Disconnect vacuum hose from EGR valve and plug hose. Perform KOER SELF-TEST. If code 34 is present, check EVR filter for obstructions. Replace if necessary. If filter is okay, replace EVR solenoid. Connect all vacuum hoses and repeat QUICK TEST  . If code 34 is not present, fault cannot be duplicated at this time. Testing is completed.
Fig 1: EGR Valve Position (EVP) & EGR Valve Regulator (EVR) Circuits
G6030
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