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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)/press the engine start/stop button, or while the ignition switch is in ON (II)/vehicle in ON mode. 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), or press the engine start/stop button to select the ON mode.
  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
  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 at the ECM/PCM, then clean the throttle body (see THROTTLE BODY CLEANING ). ■

  7. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  8. Disconnect the intake air duct from the throttle body.
  9. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  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 CLEANING ), then go to step  24 and recheck. If DTC P2101 is indicated, go to step  22.

    NO  - Go to step 13.

  13. Turn the ignition switch to LOCK (0), or press the engine start/stop button to select the OFF mode.
  14. Disconnect the throttle body 6P connector.
  15. Jump the SCS line with the HDS.
  16. Disconnect ECM/PCM connector B (49P).
  17. Check for continuity between ECM/PCM connector terminal B33 and throttle body 6P connector terminal No. 4.
    Fig 1: Checking Continuity Between ECM/PCM Connector Terminal B33 And Throttle Body 6P Connector
    G08069626Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 18.

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

  18. Disconnect ECM/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
    G08069627Courtesy of AMERICAN HONDA MOTOR CO., INC.
  20. Check for continuity between ECM/PCM connector terminals C2 and C3.
    Fig 3: Checking Continuity Between ECM/PCM Connector Terminals C2 And C3
    G08069628Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step 21.

    NO  - Repair open in the wires between the throttle body and the ECM/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
    G08069629Courtesy 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), or press the engine start/stop button to select the OFF mode.
  23. Replace the throttle body (see THROTTLE BODY REMOVAL/INSTALLATION ).
  24. Reconnect all connectors.
  25. Turn the ignition switch to ON (II), or press the engine start/stop button to select the ON mode.
  26. Reset the ECM/PCM with the HDS.
  27. Do the ECM/PCM idle learn procedure (see ECM/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
  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 ECM/PCM, then clean the throttle body (see THROTTLE BODY CLEANING ), 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 ECM/PCM if it does not have the latest software (see ECM/PCM UPDATE ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
  32. Test-drive the vehicle for several minutes in the range of these recorded freeze data parameters:
    • ENGINE SPEED
    • VEHICLE SPEED
    • APP SENSOR
  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 ECM/PCM, then clean the throttle body (see THROTTLE BODY CLEANING ). If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then go to step  32. If the ECM/PCM was substituted, go to step  1.

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

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