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DTC P2101: ETCS Malfunction

CAUTION: Do not insert your fingers into the installed throttle body when you turn the ignition switch to ON (II) or while the ignition switch is in ON (II). If you do, you will seriously injure your fingers if the throttle valve is activated.
NOTE: Before you troubleshoot, record all freeze data and any on-board snapshot, and review the general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION ).
  1. Turn the ignition switch to ON (II).
  2. Clear the DTC with the HDS.
  3. Do the ETCS TEST in the INSPECTION MENU with the HDS.
  4. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P2101 indicated? 

    YES  -Go to step  7.

    NO  -Go to step 5.

  5. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VEHICLE SPEED
    • APP SENSOR A
  6. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P2101 indicated? 

    YES  -Go to step 7.

    NO  -Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body and the PCM, then clean the throttle body (see THROTTLE BODY TEST ).

  7. Turn the ignition switch to LOCK (0).
  8. Disconnect the intake air duct from the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
  9. Turn the ignition switch to ON (II).
  10. Clear the DTC with the HDS.
  11. Do the ETCS TEST in the INSPECTION MENU with the HDS.
  12. Visually check the throttle valve operation.

    Does the throttle valve operate smoothly? 

    YES  -Clean the throttle body (see THROTTLE BODY TEST ), then go to step  25 and recheck. If DTC P2101 is indicated, go to step  22.

    NO  -Go to step 13.

  13. Turn the ignition switch to LOCK (0).
  14. Disconnect the throttle body 6P connector.
  15. Jump the SCS line with the HDS.
  16. Disconnect PCM connector B (49P).
  17. Check for continuity between PCM connector terminal B33 and throttle body 6P connector terminal No. 4.
    Fig 1: Checking Continuity Between PCM Connector Terminal B33 And Throttle Body 6P Connector Terminal No. 4
    G08054615Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 18.

    NO  -Repair an open in the wire between the throttle body and the PCM (B33), then go to step  24.

  18. Disconnect PCM connector C (49P).
  19. Connect throttle body 6P connector terminals No. 5 and No. 6 with a jumper wire.
    Fig 2: Connecting Throttle Body 6P Connector Terminals No. 5 And No. 6 With Jumper Wire
    G08054616Courtesy of AMERICAN HONDA MOTOR CO., INC.
  20. Check for continuity between PCM connector terminals C2 and C3.
    Fig 3: Checking Continuity Between PCM Connector Terminals C2 And C3
    G08054617Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 21.

    NO  -Repair an open in the wires between the throttle body and the PCM (C2, C3), then go to step  24.

  21. At the throttle body side, measure the resistance between throttle body 6P connector terminals No. 5 and No. 6 with the throttle fully closed.
    Fig 4: Measuring Resistance Between Throttle Body 6P Connector Terminals No. 5 And No. 6
    G08054618Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 1.0 kΩ or more? 

    YES  -Go to step  23.

    NO  -Go to step  30.

  22. Turn the ignition switch to LOCK (0).
  23. Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
  24. Reconnect all connectors.
  25. Turn the ignition switch to ON (II).
  26. Reset the PCM with the HDS.
  27. Do the PCM idle learn procedure (see PCM IDLE LEARN PROCEDURE ).
  28. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VEHICLE SPEED
    • APP SENSOR A
  29. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P2101 indicated? 

    YES  -Check for poor connections or loose terminals at the throttle body and the PCM, then clean the throttle body (see THROTTLE BODY TEST ), and go to step  1.

    NO  -Troubleshooting is complete. If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.

  30. Reconnect all connectors.
  31. Update the PCM if it does not have the latest software (see KNOCK SENSOR REPLACEMENT ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ).
  32. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VEHICLE SPEED
    • APP SENSOR A
  33. Check for Pending or Confirmed DTCs with the HDS.

    Is DTC P2101 indicated? 

    YES  -Check for poor connections or loose terminals at the throttle body and the PCM. If the PCM was updated, substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the PCM was substituted, go to step  1.

    NO  -If the PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT ). If any other Pending or Confirmed DTCs are indicated, go to the indicated DTC's troubleshooting.

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