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Home >> Acura >> 2003 >> MDX Base >> Repair and Diagnosis >> Engine Performance >> System >> Electronic Throttle Control System >> DTC Troubleshooting >> DTC U0107: Lost Communication with Throttle Actuator Control Module
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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  - Go to step 4.
    2. NO  - Go to step  9.
  4. Turn the ignition switch OFF within 2 seconds after clearing the DTC with the HDS.
    NOTE: If the DTC is stored, clear the DTC again.
  5. Disconnect the intake air duct from the throttle body.
  6. Press and hold the accelerator pedal fully down.
  7. Turn the ignition switch ON (II).
  8. Check the throttle valve operation.

    Does the throttle valve close fully, then open fully? 

    1. YES  - Go to step  15.
    2. NO  - If the throttle valve does not close fully after the ignition is turned ON (II), go to step  21. If the throttle valve closes fully but does not open fully, go to step  35.
  9. Start the engine.
  10. Check for Temporary DTCs or DTCs with the HDS.

    Is DTC U0107 indicated? 

    1. YES  - Go to step 11.
    2. NO  - Intermittent failure, system is OK at this time. Check for poor connections or loose terminals at the throttle actuator control module, the throttle actuator control module relay, the No. 7 DBW (15 A) fuse at the under-hood subfuse box, and the PCM.
  11. Turn the ignition switch OFF.
  12. Jump the SCS line with the HDS.
  13. Disconnect PCM connector A (73P).
  14. Check for continuity between body ground and PCM connector terminals A39 and A40.
    Fig 1: Checking Continuity Between Body Ground And PCM Connector Terminals A39 And A40
    G03639866Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  52.
    2. NO  - Repair open in the wire between the PCM (A39, A40) and G101, then go to step  49.
  15. Turn the ignition switch OFF.
  16. Jump the SCS line with the HDS.
  17. Disconnect PCM connector A (73P).
  18. Disconnect the throttle actuator control module 16P connector.
  19. Check for continuity between throttle actuator control module 16P connector terminal No. 4 and body ground.
    Fig 2: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal No. 4 And Body Ground
    G03639867Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair short in the wire between the PCM and the throttle actuator control module, then go to step  49.
    2. NO  - Go to step 20.
  20. Check for continuity between PCM connector terminal A1 and throttle actuator control module 16P connector terminal No. 4.
    Fig 3: Checking Continuity Between PCM Connector Terminal A1 And Throttle Actuator Control Module 16P Connector Terminal No. 4
    G03639868Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  47.
    2. NO  - Repair open in the wire between the PCM (A1) and the throttle actuator control module, then go to step  48.
  21. Turn the ignition switch OFF.
  22. Disconnect the throttle actuator control module 16P connector.
  23. Check for continuity between body ground and throttle actuator control module 16P connector terminals No. 2 and No. 10.
    Fig 4: Checking Continuity Between Body Ground And Throttle Actuator Control Module 16P Connector Terminals No. 2 And No. 10
    G03639869Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step 24.
    2. NO  - Repair open in the wire between the throttle actuator control module and G101, then go to step  49.
  24. Check the TAC RELAY in the DATA LIST with the HDS.

    Is it ON? 

    1. YES  - Go to step  51.
    2. NO  - Go to step 25.
  25. Turn the ignition switch OFF.
  26. Turn the ignition switch ON (II).
  27. Measure voltage between throttle actuator control module 16P connector terminal No. 6 and body ground.
    Fig 5: Measuring Voltage Between Throttle Actuator Control Module 16P Connector Terminal No. 6 And Body Ground
    G03639870Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there about 3 V or more? 

    1. YES  - Go to step 28.
    2. NO  - Go to step  41.
  28. Measure voltage between throttle actuator control module 16P connector terminal No. 1 and body ground.
    Fig 6: Measuring Voltage Between Throttle Actuator Control Module 16P Connector Terminal No. 1 And Body Ground
    G03639871Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  - Go to step  47.
    2. NO  - Go to step 29.
  29. Measure voltage between throttle actuator control relay 4P connector terminal No. 1 and body ground.
    Fig 7: Measuring Voltage Between Throttle Actuator Control Relay 4P Connector Terminal No. 1 And Body Ground
    G03639872Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    1. YES  - Go to step 30.
    2. NO  - Check the No. 7 ETC (15 A) fuse in the underhood subfuse box. If the fuse is OK, check for an open in the wire between the under-hood subfuse box and throttle actuator control relay, then go to step  49.
  30. Turn the ignition switch OFF.
  31. Remove the throttle actuator control relay.
  32. Disconnect the throttle actuator control module 16P connector.
  33. Connect throttle actuator control relay 4P connector terminal No. 2 to body ground with a jumper wire.
    Fig 8: Connecting Throttle Actuator Control Relay 4P Connector Terminal No. 2 To Body Ground With Jumper Wire
    G03639873Courtesy of AMERICAN HONDA MOTOR CO., INC.
  34. Check for continuity between throttle actuator control module 16P connector terminal No. 1 and body ground.
    Fig 9: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal No. 1 And Body Ground
    G03639874Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Replace the throttle actuator control relay, then go to step  48.
    2. NO  - Repair open in the wire between the throttle actuator control relay and the throttle actuator control module, then go to step  48.
  35. Turn the ignition switch OFF.
  36. Jump the SCS line with the HDS.
  37. Disconnect PCM connector A (73P).
  38. Disconnect the throttle actuator control module 16P connector.
  39. Check for continuity between throttle actuator control module 16P connector terminal No. 13 and body ground.
    Fig 10: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal No. 13 And Body Ground
    G03639875Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair short in the wire between the PCM and the throttle actuator control module, then go to step  48.
    2. NO  - Go to step 40.
  40. Check for continuity between PCM connector terminal A2 and throttle actuator control module 16P connector terminal No. 13.
    Fig 11: Checking Continuity Between PCM Connector Terminal A2 And Throttle Actuator Control Module 16P Connector Terminal No. 13
    G03639876Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  47.
    2. NO  - Repair open in the wire between the PCM (A2) and the throttle actuator control module, then go to step  48.
  41. Turn the ignition switch OFF.
  42. Jump the SCS line with the HDS.
  43. Disconnect PCM connector A (73P).
  44. Disconnect the throttle actuator control module 16P connector.
  45. Check for continuity between throttle actuator control module 16P connector terminal No. 6 and body ground.
    Fig 12: Checking Continuity Between Throttle Actuator Control Module 16P Connector Terminal No. 6 And Body Ground
    G03639877Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Repair short in the wire between the PCM (A29) and the throttle actuator control module, then go to step  48.
    2. NO  - Go to step 46.
  46. Check for continuity between PCM connector terminal A29 and throttle actuator control module 16P connector terminal No. 6.
    Fig 13: Checking Continuity Between PCM Connector Terminal A29 And Throttle Actuator Control Module 16P Connector Terminal No. 6
    G03639878Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    1. YES  - Go to step  51.
    2. NO  - Repair open in the wire between the PCM (A29) and the throttle actuator control module, then go to step  48.
  47. Replace the throttle body assembly (see THROTTLE BODY REMOVAL/INSTALLATION ).
  48. Turn the ignition switch ON (II).
  49. Clear the DTC with the HDS.
  50. Check for Temporary DTCs or DTCs with the HDS.

    Are any Temporary DTCs or DTCs indicated? 

    1. YES  - Go to step 51.
    2. NO  - Troubleshooting is complete.
  51. Update the PCM if it does not have the latest software, or substitute a known-good PCM (see PCM UPDATING AND SUBSTITUTION FOR TESTING ).
  52. 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 actuator control module and the PCM, 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 PCM was updated, troubleshooting is complete. If the PCM was substituted, replace the original PCM (see PCM REPLACEMENT )
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