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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? 

    1. YES -  Check for poor connections or loose terminals at the throttle body, the throttle actuator control module and the ECM, then go to step  50. If the connections are OK, go to step  6.
    2. NO -  Go to step  4.
  4. Start the engine.
  5. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC U0107 indicated? 

    1. YES -  Go to step  46.
    2. NO -  Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the throttle body, the ETCS control module relay, the throttle actuator control module, and the ECM.
  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 it open after it closes? 

    1. YES -  Go to step  12.
    2. NO -  Go to step  13.
  12. Check the throttle valve again.

    Does the throttle valve open fully? 

    1. YES -  Go to step  40.
    2. 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 No 7 And Body Ground
    G03693172Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Go to step  16.
    2. 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 ETCS control module relay (A).
    Fig 2: Removing ETCS Control Module Relay
    G03693173Courtesy of AMERICAN HONDA MOTOR CO., INC.
  17. Measure voltage between ETCS control module relay 4P connector terminal No. 2 and body ground.
    Fig 3: Measuring Voltage Between ETCS Control Module Relay 4P Connector Terminal No 2 And Body Ground
    G03693174Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step  19.
    2. NO -  Go to step  18.
  18. Check the No. 14 DBW (15 A) fuse in the under-dash fuse/relay box.

    Is the fuse OK? 

    1. YES -  Repair open in the wire between the ETCS control module relay (+B line) and the No. 14 DBW (15 A) fuse, then go to step  50.
    2. NO -  Repair short in the wire between the ETCS control module relay (+B line) and the No. 14 DBW (15 A) fuse, then go to step  50.
  19. Install the ETCS control 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 No 2 And Body Ground
    G03693175Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage for about 2 seconds? 

    1. 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.
    2. NO -  Go to step  22.
  22. Turn the ignition switch OFF.
  23. Remove the ETCS control module relay (A).
    Fig 5: Removing ETCS Control Module Relay
    G03693176Courtesy of AMERICAN HONDA MOTOR CO., INC.
  24. Check the ETCS control module relay (see POWER RELAY TEST )

    Is the ETCS control module relay OK? 

    1. YES -  Go to step  25.
    2. NO -  Replace the ETCS control module relay, then go to step  50.
  25. Turn the ignition switch ON (II).
  26. Measure voltage between ETCS control module relay 4P connector terminal No. 4 and body ground.
    Fig 6: Measuring Voltage Between ETCS Control Module Relay 4P Connector Terminal No 4 And Body Ground
    G03693177Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES -  Go to step  27.
    2. NO -  Repair open in the wire between the ETCS control module relay and PGM-FI main relay 1 (FI MAIN), then go to step  50.
  27. Turn the ignition switch OFF.
  28. Jump the SCS line with the HDS.
  29. Disconnect ECM connector D (17P).
  30. Check for continuity between ECM connector terminal D15 and ETCS control module relay 4P connector terminal No. 3.
    Fig 7: Checking Continuity Between ECM Connector Terminal D15 And ETCS Control Module Relay 4P Connector Terminal No 3
    G03693178Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Go to step  31.
    2. NO -  Repair open in the wire between the ECM (D15) and the ETCS 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 No 2 And Body Ground
    G03693179Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Repair short in the wire between the throttle actuator control module and the ETCS control module relay (+B line), then go to step  50.
    2. NO -  Go to step  32.
  32. Connect ETCS control module relay 4P connector terminal No. 1 to body ground with a jumper wire.
    Fig 9: Connecting ETCS Control Module Relay 4P Connector Terminal No 1 To Body Ground
    G03693180Courtesy 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 No 2 And Body Ground
    G03693181Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Go to step  56.
    2. NO -  Repair open in the wire between the throttle actuator control module and the ETCS 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 connector B (24P).
  38. Check for continuity between ECM connector terminal B19 and body ground.
    Fig 11: Checking Continuity Between ECM Connector Terminal B19 And Body Ground
    G03693182Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Repair short in the wire between the ECM (B19) and the throttle actuator control module, then go to step  50.
    2. NO -  Go to step  39.
  39. Check for continuity between ECM connector terminal B19 and throttle actuator control module 16P connector terminal No. 6.
    Fig 12: Checking Continuity Between ECM Connector Terminal B19 And Throttle Actuator Control Module 16P Connector Terminal No 6
    G03693183Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. 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.
    2. NO -  Repair open in the wire between the ECM (B19) 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 connector B (24P).
  44. Check for continuity between ECM connector terminal B20 and body ground.
    Fig 13: Checking Continuity Between ECM Connector Terminal B20 And Body Ground
    G03693184Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Repair short in the wire between the ECM (B20) and the throttle actuator control module, then go to step  50.
    2. NO -  Go to step  45.
  45. Check for continuity between ECM connector terminal B20 and throttle actuator control module 16P connector terminal No. 14.
    Fig 14: Checking Continuity Between ECM Connector Terminal B20 & Throttle Actuator Control Module 16P Connector
    G03693185Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. 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.
    2. NO -  Repair open in the wire between the ECM (B20) 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 connector A (31P).
  49. Check for continuity between body ground and ECM connector terminals A8 and A9 individually.
    Fig 15: Checking Continuity Between Body Ground And ECM Connector Terminals A8 And A9
    G03693186Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES -  Check for poor connections or loose terminals at the throttle body, the ETCS control relay, the throttle actuator control module, and the ECM, then go to step  1.
    2. NO -  Repair open in the wire between the ECM (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 with the HDS.
  54. Do the ECM idle learn procedure (see ECM IDLE LEARN PROCEDURE ).
  55. Check for Temporary DTCs or DTCs with the HDS.

    Are any Temporary DTCs or DTCs indicated? 

    1. YES -  If DTC U0107 is indicated, check for poor connections or loose terminals at the throttle body, the ETCS control module relay, the throttle actuator control module, and the ECM, then go to step  1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
    2. NO -  Troubleshooting is complete.
  56. Update the ECM if it does not have the latest software, or substitute a known-good ECM (see UPDATING THE ECM ).
  57. Check for Temporary DTCs or DTCs with the HDS.

    Are any Temporary DTCs or DTCs indicated? 

    1. YES -  If DTC U0107 is indicated, check for poor connections or loose terminals at the throttle body, the ETCS control module relay, the throttle actuator control module, and the ECM, then go to step  1. If any other Temporary DTCs or DTCs are indicated, go to the indicated DTC's troubleshooting.
    2. NO -  If the ECM was updated, troubleshooting is complete. If the ECM was substituted, replace the original ECM (see ECM REPLACEMENT ).
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