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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 P1404 - EGR Valve Closed Position Error >> Diagnostic Procedures
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Diagnostic Procedures

  1. Install scan tool. Turn ignition on, engine off. Using scan tool, compare learned closed pintle position to actual pintle position voltage. If voltage differs, go to next step. If voltage is the same, go to step 3).
  2. Check for backed-out, damaged or loose terminal connections. Check for intermittent open in EGR valve harness connector terminals 'C'" and "D" circuits. Repair as necessary.
  3. If voltage difference is greater than .15 volt, go to step 5). If voltage difference is not greater than .15 volts, go to next step.
  4. Using scan tool, locate DTC P1404 in code status. Road test vehicle to obtain a PASS or FAIL diagnostic. If a PASS is obtained, problem is intermittent. See DIAGNOSTIC AIDS. If a FAIL is obtained, go to step 9).
  5. If voltage is greater than 1.5 volts and engine runs okay, go to next step. If voltage is greater than 1.5 volts and 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 PCM and EGR harness connector terminal "A". If circuit is okay, replace faulty PCM.
  6. Disconnect EGR valve harness connector. If pintle voltage is now less than 1.5 volts, go to step 8). If pintle voltage is not less than 1.5 volts, go to next step.
  7. Turn ignition off. Disconnect PCM harness connector J2. Remove circuit from EGR harness connector terminal "C" at PCM harness connector. Reconnect PCM harness connector. Turn ignition on. Check voltage at disconnected terminal. If voltage reading is greater than .15 volt, repair short to ground in circuit. If voltage reading is not greater than .15 volt, replace PCM.
  8. Using test light connected to battery voltage, probe EGR valve harness connector terminal "B". If test light illuminates, go to next step. If test light does not illuminate, check circuit for open or proper terminal connection. Repair as necessary. If circuit or terminals are okay, replace PCM.
  9. Start engine. Using scan tool, command EGR valve to full open (100) and then back to closed position for 3 times. Drive vehicle to obtain a PASS or FAIL diagnosis. Drive vehicle at sufficient time and distance to obtain at least 4 or more EGR openings. If a PASS is obtained, go to next step. If a FAIL is obtained, go to step 11).
  10. Problem was likely debris in EGR pintle. Clean EGR valve. Clear DTCs and test drive vehicle.
  11. Replace EGR valve. Check and clean EGR port for carbon or debris. Road test vehicle and verify diagnostic PASS.
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