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DTC U0107: Lost Communication With Throttle Actuator Control Module

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 ON (II).
  2. Clear the DTC with the HDS.
  3. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC U0107 indicated? 

    YES  - Check for poor connections or loose terminals at the throttle body, the throttle actuator control module relay, the throttle actuator control module, and the ECM/PCM, then go to step  50. If the connections are OK, go to step  6.

    NO  - Go to step  4.

  4. Start the engine.
  5. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC U0107 indicated? 

    YES  - Go to step  46.

    NO  - Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the throttle body, the throttle actuator control module relay, the throttle actuator control module, and the ECM/PCM.

  6. Clear the DTC with the HDS.
  7. Turn the ignition switch OFF.
  8. Disconnect the intake air duct from the throttle body.
  9. Press the accelerator pedal to the floor.
  10. Turn the ignition switch ON (II).
  11. Check the throttle valve operation.

    Does the valve open after it closes? 

    YES  - Go to step  12.

    NO  - Go to step  13.

  12. Check the throttle valve again.

    Does the throttle valve open fully? 

    YES  - Go to step  40.

    NO  - Go to step  34.

  13. Turn the ignition switch OFF.
  14. Disconnect the throttle actuator control module 16P connector.
  15. Check for continuity between throttle actuator control module 16P connector terminal No. 7 and body ground.
    Fig 1: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal 7 And Body Ground
    G05454713Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step  16.

    NO  - Repair open in the wire between the throttle body, the throttle actuator control module, and G101, then go to step  50.

  16. Remove the throttle actuator control module relay (A).
    Fig 2: Identifying Throttle Actuator Control Module Relay
    G05454714Courtesy of AMERICAN HONDA MOTOR CO., INC.
  17. Measure voltage between throttle actuator control module relay 4P connector terminal No. 1 and body ground.
    Fig 3: Measuring Voltage Between Throttle Actuator Control Module Relay 4P Connector Terminal 1 And Body Ground
    G05454715Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  19.

    NO  - Go to step  18.

  18. Check the No. 32 DBW (15 A) fuse in the under-dash subfuse/relay box.

    Is the fuse OK? 

    YES  - Repair open in the wire between the throttle actuator control module relay (+B line) and the No. 32 DBW (15 A) fuse, then go to step  50.

    NO  - Repair short in the wire between the throttle actuator control module relay (+B line) and the No. 32 DBW (15 A) fuse, then go to step  50.

  19. Install the throttle actuator control module relay.
  20. Turn the ignition switch ON (II).
  21. Measure voltage between throttle actuator control module 16P connector terminal No. 2 and body ground.
    Fig 4: Measuring Voltage Between Throttle Actuator Control Module 16P Connector Terminal 2 And Body Ground
    G05454716Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage for about 2 seconds? 

    YES  - Substitute a known-good throttle actuator control module (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ), then go to step  50 and recheck. If DTC U0107 is not indicated, replace the original throttle actuator control module (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ), then go to step  50.

    NO  - Go to step  22.

  22. Turn the ignition switch OFF.
  23. Remove the throttle actuator control module relay (A).
    Fig 5: Identifying Throttle Actuator Control Module Relay
    G05454717Courtesy of AMERICAN HONDA MOTOR CO., INC.
  24. Check the throttle actuator control module relay (see POWER RELAY TEST ).

    Is the throttle actuator control module relay OK? 

    YES  - Go to step  25.

    NO  - Replace the throttle actuator control module relay, then go to step  50.

  25. Turn the ignition switch ON (II).
  26. Measure voltage between throttle actuator control module relay 4P connector terminal No. 4 and body ground.
    Fig 6: Measuring Voltage Between Throttle Actuator Control Module Relay 4P Connector Terminal 4 And Body Ground
    G05454718Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  - Go to step  27.

    NO  - Repair open in the wire between the throttle actuator control module relay and PGM-FI main relay 1 (Fl MAIN), then go to step  50.

  27. Turn the ignition switch OFF.
  28. Jump the SCS line with the HDS.
  29. Disconnect ECM/PCM connector D (17P).
  30. Check for continuity between ECM/PCM connector terminal D15 and throttle actuator control module relay 4P connector terminal No. 3.
    Fig 7: Checking Continuity Between ECM/PCM And Throttle Actuator Control Module Relay Connector Terminals
    G05454719Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step  31.

    NO  - Repair open in the wire between the ECM/PCM (D15) and the throttle actuator control module relay, then go to step  50.

  31. Check for continuity between throttle actuator control module 16P connector terminal No. 2 and body ground.
    Fig 8: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal 2 And Body Ground
    G05454720Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short in the wire between the throttle actuator control module and the throttle actuator control module relay (+B line), then go to step  50.

    NO  - Go to step  32.

  32. Connect throttle actuator control module relay 4P connector terminal No. 2 to body ground with a jumper wire.
    Fig 9: Connecting Throttle Actuator Control Module Relay 4P Connector Terminal 2 To Body Ground With Jumper Wire
    G05454721Courtesy of AMERICAN HONDA MOTOR CO., INC.
  33. Check for continuity between throttle actuator control module 16P connector terminal No. 2 and body ground.
    Fig 10: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal 2 And Body Ground
    G05454722Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Go to step  56.

    NO  - Repair open in the wire between the throttle actuator control module and the throttle actuator control module relay (+B line), then go to step  50.

  34. Turn the ignition switch OFF.
  35. Jump the SCS line with the HDS.
  36. Disconnect the throttle actuator control module 16P connector (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ).
  37. Disconnect ECM/PCM connector D (17P).
  38. Check for continuity between ECM/PCM connector terminal D13 and body ground.
    Fig 11: Checking Continuity Between ECM/PCM Connector Terminal D13 And Body Ground
    G05454723Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short in the wire between the ECM/PCM (D13) and the throttle actuator control module, then go to step  50.

    NO  - Go to step  39.

  39. Check for continuity between ECM/PCM connector terminal D13 and throttle actuator control module 16P connector terminal No. 6.
    Fig 12: Checking Continuity Between ECM/PCM And Throttle Actuator Control Module Connector Terminals
    G05454724Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Substitute a known-good throttle actuator control module (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ), then go to step  50 and recheck. If DTC U0107 is not indicated, replace the original throttle actuator control module (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ), then go to step  50. If DTC U0107 is indicated, go to step  56.

    NO  - Repair open in the wire between the ECM/PCM (D13) and the throttle actuator control module, then go to step  50.

  40. Turn the ignition switch OFF.
  41. Jump the SCS line with the HDS.
  42. Disconnect the throttle actuator control module 16P connector.
  43. Disconnect ECM/PCM connector D (17P).
  44. Check for continuity between ECM/PCM connector terminal D14 and body ground.
    Fig 13: Checking Continuity Between ECM/PCM Connector Terminal D14 And Body Ground
    G05454725Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Repair short in the wire between the ECM/PCM (D14) and the throttle actuator control module, then go to step  50.

    NO  - Go to step  45.

  45. Check for continuity between ECM/PCM connector terminal D14 and throttle actuator control module 16P connector terminal No. 14.
    Fig 14: Checking Continuity Between ECM/PCM And Throttle Actuator Control Module Connector Terminals
    G05454726Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Substitute a known-good throttle actuator control module (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ), then go to step  50 and recheck. If DTC U0107 is not indicated, replace the original throttle actuator control module (see THROTTLE ACTUATOR CONTROL MODULE REPLACEMENT ), then go to step  50. If DTC U0107 is indicated, go to step  56.

    NO  - Repair open in the wire between the ECM/PCM (D14) and the throttle actuator control module, then go to step  50.

  46. Turn the ignition switch OFF.
  47. Jump the SCS line with the HDS.
  48. Disconnect ECM/PCM connector A (31P).
  49. Check for continuity between body ground and ECM/PCM connector terminals A8 and A9 individually.
    Fig 15: Checking Continuity Between Body Ground And ECM/PCM Connector Terminals
    G05454727Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  - Check for poor connections or loose terminals at the throttle body, the throttle actuator control module relay, the throttle actuator control module, and the ECM/PCM, then go to step  1.

    NO  - Repair open in the wire between the ECM/PCM (A8, A9) and G101, then go to step  50.

  50. Turn the ignition switch OFF.
  51. Reconnect all connectors.
  52. Turn the ignition switch ON (II).
  53. Reset the ECM/PCM with the HDS.
  54. Do the ECM/PCM idle learn procedure (see ECM/PCM IDLE LEARN PROCEDURE ).
  55. Check for Temporary DTCs or DTCs with the HDS.

    If DTC U0107 indicated? 

    YES  - Check for poor connections or loose terminals at the throttle body, the throttle actuator control module relay, the throttle actuator control module, and the ECM/PCM, then go to step  1.

    NO  - Troubleshooting is complete. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

  56. Reconnect all connectors.
  57. Update the ECM/PCM if it does not have the latest software (see UPDATING THE ECM/PCM ), or substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ).
  58. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC U0107 indicated? 

    YES  - Check for poor connections or loose terminals at the throttle body, the throttle actuator control module relay, the throttle actuator control module, and the ECM/PCM. If the ECM/PCM was updated, substitute a known-good ECM/PCM (see SUBSTITUTING THE ECM/PCM ), then recheck. 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 Temporary DTCs or DTCs are indicated, go to the indicated DTCs troubleshooting.

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