LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Honda >> 2000 >> S2000 >> Repair and Diagnosis >> Engine Performance >> System >> Pulsed Secondary Air Injection System >> DTC Troubleshooting >> DTC P0411: Secondary Air Injection System Incorrect Flow
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC P0411: Secondary Air Injection System Incorrect Flow

Special Tools Required 

Vacuum pump/gauge, 0-30 in.Hg, Snap-on YA4000A or equivalent, commercially available

NOTE: Before you troubleshoot, record all freeze data and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Reset the ECM (see HOW TO RESET THE ECM ).
  2. Make sure the engine coolant temperature is over 32 °F (0 °C) and below 158 °F (60 °C) with a scan tool or the HDS.
  3. Start the engine. While the air pump operates, let the engine idle without load (in neutral) for at least 10 seconds.
  4. Check for a Temporary DTC with a scan tool or the HDS.

    Is Temporary DTC P0411 indicated? 

    1. YES -  Go to step 5.
    2. NO -  Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the air control valve vacuum control solenoid valve and at the ECM.
  5. Turn the ignition switch OFF.
  6. Check the vacuum lines of the air pump system for misrouting, leakage, breakage, and clogging.

    Are the vacuum lines OK? 

    1. YES -  Go to step 7.
    2. NO -  Repair or replace vacuum lines as necessary.
  7. Reset the ECM (see HOW TO RESET THE ECM ).
  8. Make sure the engine coolant temperature is over 32 °F (0 °C) and below 158 °F (60 °C) with a scan tool or the HDS.
  9. Disconnect the vacuum hose from the air control valve (A), and connect a commercially available vacuum pump/gauge, 0-30 in.Hg, to the hose.
    Fig 1: Disconnecting Vacuum Hose From Air Control Valve
    G03692889Courtesy of AMERICAN HONDA MOTOR CO., INC.
  10. Start the engine. While the air pump operates, let the engine idle without load (in neutral).

    Is there vacuum while the air pump operates? 

    1. YES -  Go to step 11.
    2. NO -  Go to step  16.
  11. Turn the ignition switch OFF.
  12. Disconnect the air control valve vacuum control solenoid valve 2P connector.
  13. Check for continuity between air control valve vacuum control solenoid valve 2P connector terminal No. 2 and body ground.
    Fig 2: Checking Continuity Between Air Control Valve Vacuum Control Solenoid Valve 2P Connector And Body Ground
    G03692890Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Go to step 14.
    2. NO -  Replace the air control valve vacuum control solenoid valve.
  14. Disconnect ECM connector A (32P).
  15. Check for continuity between air control valve vacuum control solenoid valve 2P connector terminal No. 2 and body ground.
    Fig 3: Checking Continuity Between Air Control Valve Vacuum Control Solenoid Valve 2P Connector And Body Ground
    G03692891Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Repair short in the wire between the air control valve vacuum control solenoid valve and the ECM (A2).
    2. NO -  Substitute a known-good ECM (see HOW TO SUBSTITUTE THE ECM FOR TESTING PURPOSES ) and recheck. If the symptom/indication goes away, replace the original ECM (see ECM REPLACEMENT ).
  16. Turn the ignition switch OFF.
  17. Check the No. 6 ACG (15 A) fuse in the under-dash fuse/relay box.

    Is the fuse OK? 

    1. YES -  Go to step 18.
    2. NO -  Repair short in the wire between the No. 6 ACG (15 A) fuse and the gauge assembly. Then replace the No. 6 ACG (15 A) fuse.
  18. Disconnect the air control valve vacuum control solenoid valve 2P connector.
  19. Turn the ignition switch ON (II).
  20. Measure voltage between air control valve vacuum control solenoid valve 2P connector terminal No. 1 and body ground.
    Fig 4: Measuring Voltage Between Air Control Valve Vacuum Control Solenoid Valve 2P Connector And Body Ground
    G03692892Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step 21.
    2. NO -  Repair open in the wire between the No. 6 ACG (15 A) fuse in the under-dash fuse/relay box and the air control solenoid valve.
  21. Turn the ignition switch OFF.
  22. Reconnect the air control valve vacuum control solenoid valve 2P connector.
  23. Disconnect ECM connector A (32P).
  24. Turn the ignition switch ON (II), and measure voltage between ECM connector terminal A2 and body ground.
    Fig 5: Measuring Voltage Between ECM Connector Terminal A2 And Body Ground
    G03692893Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there less than 1.0 V? 

    1. YES -  Repair open in the wire between the air control valve vacuum control solenoid valve and the ECM (A2). If the wire is OK, replace the air control valve vacuum control solenoid valve.
    2. NO -  Substitute a known-good ECM (see HOW TO SUBSTITUTE THE ECM FOR TESTING PURPOSES ) and recheck. If the symptom/indication goes away, replace the original ECM (see ECM REPLACEMENT ).
scientia non olet · About LEMON Manuals