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DTC P0403: EGR Control Circuit Malfunction

CAUTION: When substituting or replacement of PCM is recommended, see PCM REMOVAL & REPLACEMENT  for important precautions.
  1. Turn ignition on. Using Honda PGM Tester or the HDS, do the DTC CLEAR in the CLEAR menu.
  2. Start engine. Hold engine speed at 3000 RPM with no loads (A/T in Park or Neutral) until radiator fan comes on, then let engine idle.
  3. With the Honda PGM tester or the HDS, do the EGR test in the INSPECTION menu. If the EGR system is OK, problem is intermittent, system is OK at this time. Check for poor connections or loose terminals at EGR valve and PCM connectors. If EGR system is not OK, go to next step.
  4. Turn ignition off. Disconnect EGR 6-pin connector. See Figure . At the EGR valve side, measure resistance between connector terminals No. 4 and 6. If there is about 6.3-6.7 ohms, go to next step. If there is not about 6.3-6.7 ohms, go to step  8 .
  5. Disconnect PCM harness connector "A". See Figure . Check for continuity between ground and PCM harness connector terminal A15 (Blue/Red wire). If there is continuity, repair short in wire between PCM harness connector terminal A15 and EGR valve. Go to step  9 . If there is no continuity, go to next step.
  6. With a fused jumper wire, connect EGR connector terminal No. 4 to ground. Check for continuity between ground and PCM harness connector terminal A15 (Blue/Red wire). If there is continuity, go to next step. If there is no continuity, repair open in wire between PCM harness connector terminal A15 and EGR valve. Go to step  9 .
  7. Check for continuity between ground and EGR 6-pin harness connector terminal No. 6 (Black wire). If there is continuity, update the PCM if it does not have the latest software, or substitute a known-good PCM. Go to step  9 . If there is no continuity, repair open in wire between ground and EGR 6-pin harness connector terminal No. 6. Go to step  9 .
  8. Replace EGR valve.
  9. Turn ignition on. With the Honda PGM tester or the HDS, do PCM RESET in the CLEAR menu. Do the PCM idle learn procedure. See PCM IDLE LEARN PROCEDURE  . Go to next step.
  10. Start engine. Hold engine speed at 3000 RPM with no loads (A/T in Park or Neutral) until radiator fan comes on, then let engine idle.
  11. Check for Temporary DTCs or DTCs in the DTC menu. If DTC P0403 is set, check for poor connections or loose terminals at EGR valve and PCM harness connector. Go to step  1 . If any other Temporary DTCs or DTCs are set, troubleshoot those indicated. If there are no Temporary DTCs or DTCs set, PCM was updated, troubleshooting is complete. If PCM was substituted, replace original PCM.
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