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Home >> Saturn >> 1998 >> SC2 Automatic, MP6 >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Diagnostic Trouble Codes >> DTC P0404 - EGR Pintle Position Error >> Diagnostic Procedures
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Diagnostic Procedures

  1. Turn ignition on, engine off. Using scan tool, command EGR valve open at different increments. Verify actual EGR position follows desired position percentage as valve opens. If desired percentage is accomplished, problem is intermittent. See DIAGNOSTIC AIDS. If desired percentage is not accomplished, go to next step.
  2. Using scan tool, monitor EGR pintle position voltage. If voltage is greater than 1.5 volts, go to next step. If voltage is not greater than 1.5 volts, go to step 5).
  3. Start engine. If engine idles and runs okay, disconnect EGR harness connector, then go to next step. If engine runs rough or stalls, disconnect EGR harness connector. If engine does not smooth out, go to next step. If engine smooths out, check for short to ground in circuit between EGR harness connector terminal "A" (Light Blue wire) to PCM. Repair as necessary. If circuit is okay, replace PCM.
  4. Connect a test light between battery voltage and EGR harness connector terminal "B" (Black wire). If test light illuminates, go to step 8). If test light does not illuminate, check for open in Black wire between EGR and PCM or for terminal tightness. Repair as necessary. If circuit and terminals are okay, replace PCM.
  5. Disconnect EGR harness connector. Turn ignition on, engine off. Using a test light, backprobe test light between PCM harness connector terminals No. J3C16 (Black wire) and No. J2B11 (Pink wire). If test light illuminates, go to step 7). If test light does not illuminate, go to next step.
  6. Check voltage between Pink wire and ground. If voltage reading is greater than 11 volts, go to step 4). If voltage reading is not greater than 11 volts, check if DTC P0443 is also present. If P0443 is present, check EGR fuse. If only DTC P0404 is present, repair open in Pink wire between EVAP purge solenoid and PCM.
  7. Using a test light, backprobe test light between PCM harness connector terminals No. J2B10 (Light Blue wire) and No. J2B11 (Pink wire). Using scan tool, command EGR valve full open (100 percent). If test light illuminates, go to next step. If test light does not illuminate, check for terminal tightness or open/short in circuit. Repair as necessary. If circuit and terminals are okay, replace faulty PCM.
  8. Using scan tool, again command EGR valve to full open (100 percent) then back to closed position. Repeat for 3 times. Drive vehicle to obtain a PASS or FAIL diagnostic. Ensure vehicle is driven for a sufficient time and distance to obtain at least 4 EGR valve openings. If a diagnostic PASS is obtained, go to next step. If a diagnostic FAIL is obtained, go to step 10).
  9. Problem was most likely caused by debris in EGR pintle. Clean EGR valve. Clear DTCs and test drive vehicle again.
  10. Replace EGR valve. Check and clean carbon deposit or debris in EGR supply port. Road test vehicle and verify diagnostic PASS result.
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