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DLC Circuit Troubleshooting

NOTE:
  • If you suspect the HDS or the HDS DLC cable may be the source of the communication problem, verify that they are working properly by connecting them to a known-good, like vehicle and system, and checking for communication problems.
  • Information marked with an asterisk (*1) applies to '09-11 models.
  • Information marked with an asterisk (*2) applies to '12 model.
  1. Turn the ignition switch to LOCK (0).
  2. Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
  3. Turn the ignition switch to ON (II), and read the HDS.

    Does the HDS identify the vehicle? 

    YES  -Go to step 4.

    NO  -Go to step  21.

  4. Check for Pending DTCs or Confirmed DTCs in the PGM-FI system with the HDS.

    Are any Pending DTCs or Confirmed DTCs indicated? 

    YES  -Go to the indicated DTC's troubleshooting. ■

    NO  -

    • If the HDS does not communicate with the SRS system, Go to step 5.
    • If the HDS does not communicate with the VSA system, Go to step  7.
    • If the HDS does not communicate with the TPMS system, Go to step  9.
    • If the HDS does not communicate with the VTM-4 system, Go to step  11.
    • If the HDS does not communicate with the BODY ELECTRICAL system, Go to step  13.
  5. Turn the ignition switch to LOCK (0).
  6. Turn the ignition switch to ON (II), and watch the SRS indicator.

    Does the SRS indicator come on and go off? 

    YES  -Go to step 15.

    NO  -Go to the SRS system's general troubleshooting information (see GENERAL TROUBLESHOOTING INFORMATION )

  7. Turn the ignition switch to LOCK (0).
  8. Turn the ignition switch to ON (II), and watch the VSA indicator.

    Does the VSA indicator come on and go off? 

    YES  -Go to step  15.

    NO  -Go to the VSA system's troubleshooting information for ABS indicator, brake system indicator, VSA indicator does not go off (see SYMPTOM TROUBLESHOOTING INDEX ).

  9. Turn the ignition switch to LOCK (0).
  10. Turn the ignition switch to ON (II), and watch the TPMS indicator.

    Does the TPMS indicator come on and go off? 

    YES  -Go to step  15.

    NO  -Go to the TPMS symptom troubleshooting for TPMS indicator does not go off, and no DTCs are stored (see GENERAL TROUBLESHOOTING INFORMATION ).

  11. Turn the ignition switch to LOCK (0).
  12. Turn the ignition switch to ON (II), and watch the VTM-4 indicator.

    Does the VTM-4 LOCK indicator come on and go off? 

    YES  -Go to step 13.

    NO  -Go to the rear differential (VTM-4) system's troubleshooting (see GENERAL TROUBLESHOOTING INFORMATION ).

  13. Do the gauge self-diagnostic function (see SELF-DIAGNOSTIC FUNCTION ).
  14. Check the gauge display.

    Is Error 2 indicated? 

    YES  -Check for B-CAN system DTCs (see GENERAL TROUBLESHOOTING INFORMATION ). ■

    NO  -Go to step 15.

  15. Turn the ignition switch to LOCK (0), then do the battery terminal disconnection procedure (see BATTERY TEST ), and wait at least 3 minutes before starting work.
  16. Disconnect the HDS from the DLC.
  17. Check for continuity between DLC terminal No. 7 and body ground.
    Fig 1: Checking Continuity Between DLC Terminal No. 7 And Body Ground
    G05964504Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 18.

    NO  -Go to step 19.

  18. Continue to check for continuity between DLC terminal No. 7 and body ground while disconnecting these connectors, one at a time:
    • SRS unit connector A (28P)*1/(39P)*2
    • VSA modulator-control unit 46P connector
    • TPMS control unit 20P connector
    • VTM-4 control unit connector A (22P)
    • Audio unit 24P connector
    • Under-dash fuse/relay box connector P (30P)

    Does continuity go away when one of the above connectors is disconnected? 

    YES  -Replace the part that caused an open when it was disconnected. ■

    NO  -Repair short in the wire between the DLC (K-line) and the VSA modulator-control unit, the SRS unit, the TPMS control unit, the VTM-4 control unit, or the audio unit. ■

  19. Connect DLC terminal No. 7 to body ground with a jumper wire.
    Fig 2: Connecting DLC Terminal No. 7 To Body Ground With Jumper Wire
    G05964505Courtesy of AMERICAN HONDA MOTOR CO., INC.
  20. Check for continuity between body ground and the following connector terminals, with all listed control units disconnected.
    CONNECTOR TERMINAL REFERENCE CHART

    Connector Terminal
    SRS unit A(28P)*1/(39P)*2 No. 24*1/No. 18*2 (LT BLU)
    VSA modulator-control unit 46P No. 15 (LT BLU)
    TPMS control unit A (20P) No. 9 (LT BLU)
    VTM-4 control unit A (22P) No. 18 (LT BLU)
    Audio unit 24P No. 3 (LT BLU)
    Under-dash fuse/relay box P (30P) No. 6 (LT BLU)

    Is there continuity between the DLC terminal and each of the terminals in the chart? 

    YES  -Replace the part that does not communicate with the HDS. ■

    NO  -Repair open in the wire between the DLC (K-line) and the appropriate connector. ■

  21. Check for B-CAN system DTCs without the HDS (see GENERAL TROUBLESHOOTING INFORMATION ).

    Is DTC 1178 indicated? 

    YES  -Go to step  32.

    NO  -Go to step 22.

  22. Turn the ignition switch to LOCK (0).
  23. Disconnect the HDS from the DLC.
  24. Measure the voltage between DLC terminal No. 16 and body ground.
    Fig 3: Measuring Voltage Between DLC Terminal No. 16 And Body Ground
    G05964506Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 25.

    NO  -Repair open in the wire between DLC terminal No. 16 and the No. 8 +B IGP (15 A) fuse in the under-hood fuse/relay box. ■

  25. Measure the voltage between DLC terminals No. 4 and No. 16.
    Fig 4: Measuring Voltage Between DLC Terminals No. 4 And No. 16
    G05964507Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 26.

    NO  -Repair open in the wire between DLC terminal No. 4 and body ground (G402) (see DASHBOARD WIRE HARNESS (RIGHT BRANCH) ). ■

  26. Connect the HDS to the DLC (see GENERAL TROUBLESHOOTING INFORMATION ).
  27. Jump the SCS line with the HDS.
  28. Disconnect PCM connector A (49P).
  29. Disconnect the HDS from the DLC.
  30. Check for continuity between PCM connector terminal A48 and DLC terminal No. 6.
    Fig 5: Connecting DLC Terminal No. 6 To Body Ground With Jumper Wire
    G00512316Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 31.

    NO  -Repair an open in the wire between the PCM (A48) and DLC terminal No. 6.

  31. Check for continuity between PCM connector terminal A49 and DLC terminal No. 14.
    Fig 6: Checking Continuity Between PCM Connector Terminal A48 And Body Ground
    G00512317Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). ■

    NO  -Repair open in the wire between the PCM (A49) and DLC terminal No. 14. ■

  32. Try to start the engine.

    Does the engine start and idle? 

    YES  -Go to the F-CAN circuit troubleshooting (see F-CAN CIRCUIT TROUBLESHOOTING ). ■

    NO  -Go to step 33.

  33. Turn the ignition switch to LOCK (0).
  34. Check the No. 23 +B IG MAIN (60 A) fuse in the under-hood fuse/relay box.

    Is the fuse OK? 

    YES  -Repair open in the wire between the No. 23 +B IG MAIN (60 A) fuse and the ignition switch. If the wire is OK, Go to step 35.

    NO  -Repair short in the wire between the No. 23 +B IG MAIN (60 A) fuse and the ignition switch. Also replace the No. 23 +B IG MAIN (60 A) fuse. ■

  35. Inspect the No. 8 FI ECU (PCM) (15 A) fuse in the under-hood fuse/relay box.

    Is the fuse OK? 

    YES  -Go to step  42.

    NO  -Go to step 36.

  36. Remove the blown No. 8 FI ECU (PCM) (15 A) fuse from the under-hood fuse/relay box.
  37. Remove the left kick panel (see TRIM REMOVAL/INSTALLATION - DOOR AREAS ), then remove PGM-FI main relay 1 (A) from the driver's under-dash fuse/relay box.
    Fig 7: Identifying PGM-FI Main Relay 1 (FI MAIN) From Driver's Under-Dash Fuse/Relay Box
    G05964512Courtesy of AMERICAN HONDA MOTOR CO., INC.
  38. Check for continuity between body ground and PGM-FI main relay 1 4P connector terminals No. 1 and No. 4 individually.
    Fig 8: Checking Continuity Between Body Ground And PGM-FI Main Relay 1 (FI Main) 4P Connector Terminals No. 1 And No. 4
    G05964513Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Replace the under-dash fuse/relay box (see UNDER-DASH FUSE/RELAY BOX ). Also replace the No. 8 FI ECU (PCM) (15 A) fuse.

    NO  -Go to step 39.

  39. While disconnecting each of the parts or connectors below, one at a time, check for continuity between PGM-FI main relay 1 4P connector terminal No. 2 and body ground.
    • PGM-FI main relay 2
    • PCM connector B (49P)
    • Each injector 2P connector
    • Camshaft position (CMP) sensor 3P connector
    • Crankshaft position (CKP) sensor A/B 6P connector
    • Electronic throttle control system (ETCS) control relay
    • MAF sensor/IAT sensor 5P connector
    Fig 9: Checking Continuity Between PGM-FI Main Relay 1 (FI MAIN) 4P Connector Terminal No. 2 And Body Ground
    G05964514Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Does continuity go away when one of the above parts or connector is disconnected? 

    YES  -Replace the part that made the short to body ground go away when disconnected. If the part is the PCM, update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). Also replace the No. 8 FI ECU (PCM) (15 A) fuse. ■

    NO  -Go to step 40.

  40. Disconnect the connectors from these parts:
    • PGM-FI main relay 2 (FUEL PUMP)
    • PCM connector B (49P)
    • Injectors
    • Camshaft position (CMP) sensor
    • Crankshaft position (CKP) sensor A/B
    • Electronic throttle control system (ETCS) control relay
    • MAF sensor/IAT sensor
  41. Check for continuity between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 2 and body ground.
    Fig 10: Checking Continuity Between PGM-FI Main Relay 1 (FI MAIN) 4P Connector Terminal No. 2 And Body Ground
    G05964515Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair short in the wire between PGM-FI main relay 1 (FI MAIN) and each part. Also replace the No. 8 FI ECU (PCM) (15 A) fuse. ■

    NO  -Replace PGM-FI main relay 1 (FI MAIN). Also replace the No. 8 FI ECU (PCM) (15 A) fuse. ■

  42. Inspect the No. 19 IG FUEL PUMP (15 A) fuse in the under-dash fuse/relay box.

    Is the fuse OK? 

    YES  -Go to step  54.

    NO  -Go to step 43.

  43. Remove the blown No. 19 IG FUEL PUMP (15 A) fuse from the under-dash fuse/relay box.
  44. Remove PGM-FI main relay 2 (FUEL PUMP) (A) from the driver's under-dash fuse/relay box.
    Fig 11: Identifying PGM-FI Main Relay 2 (Fuel Pump) From Driver's Under-Dash Fuse/Relay Box
    G05964516Courtesy of AMERICAN HONDA MOTOR CO., INC.
  45. Test PGM-FI main relay 2 (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Go to step 46.

    NO  -Replace PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 19 IG FUEL PUMP (15 A) fuse. ■

  46. Check for continuity between PGM-FI main relay 2 4P connector terminal No. 1 and body ground.
    Fig 12: Checking Continuity Between PGM-FI Main Relay 2 (Fuel Pump) 4P Connector Terminal No. 2 And Body Ground
    G05964517Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 47.

    NO  -Go to step  50.

  47. Jump the SCS line with the HDS.
  48. Disconnect PCM connector B (49P).
  49. Check for continuity between PCM connector terminal B42 and body ground.
    Fig 13: Checking Continuity Between PCM Connector Terminal B42 And Body Ground
    G00512318Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair short in the wire between the No. 19 IG FUEL PUMP (15 A) fuse and the PCM (B42), between the No. 19 IG FUEL PUMP (15 A) fuse and PGM-FI main relay 2 (FUEL PUMP), or between the No. 19 IG FUEL PUMP (15 A) fuse and the immobilizer control unit-receiver. Also replace the No. 19 IG FUEL PUMP (15 A) fuse. ■

    NO  -Replace the No. 19 IG FUEL PUMP (15 A) fuse, and update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). ■

  50. Remove the rear seat (see REAR SEAT REMOVAL/INSTALLATION ).
  51. Remove the access panel from the floor, then disconnect the fuel tank unit 5P connector (see FUEL TANK UNIT REMOVAL AND INSTALLATION ).
  52. Check for continuity between fuel pump 5P connector terminal No. 5 and body ground.
    Fig 14: Checking Continuity Between Fuel Pump 5P Connector Terminal No. 5 And Body Ground
    G05964519Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair short in the wire between the fuel pump and PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 19 IG FUEL PUMP (15 A) fuse. ■

    NO  -Go to step 53.

  53. Reinstall PGM-FI main relay 2 (FUEL PUMP) (A).
    Fig 15: Identifying PGM-FI Main Relay 2 (Fuel Pump)
    G05964520Courtesy of AMERICAN HONDA MOTOR CO., INC.
  54. Check for continuity between fuel pump 5P connector terminal No. 5 and body ground.
    Fig 16: Checking Continuity Between Fuel Pump 5P Connector Terminal No. 5 And Body Ground
    G05964521Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Replace PGM-FI main relay 2 (FUEL PUMP). Also replace the No. 19 IG FUEL PUMP (15 A) fuse. ■

    NO  -Check the fuel pump, and replace it if needed (see FUEL PUMP/FUEL GAUGE SENDING UNIT REPLACEMENT ). Also replace the No. 19 IG FUEL PUMP (15 A) fuse. ■

  55. Jump the SCS line with the HDS.
  56. Disconnect PCM connectors A (49P) and B (49P).
  57. Turn the ignition switch to ON (II).
  58. Measure the voltage between PCM connector terminal B42 and body ground.
    Fig 17: Measuring Voltage Between PCM Connector Terminal B42 And Body Ground
    G05964522Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 59.

    NO  -Repair open in the wire between the No. 19 IG FUEL PUMP (15 A) fuse and the PCM (B42). ■

  59. Measure the voltage between PCM connector terminal A6 and body ground.
    Fig 18: Measuring Voltage Between PCM Connector Terminal A6 And Body Ground
    G05964523Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step  65.

    NO  -Go to step 60.

  60. Turn the ignition switch to LOCK (0).
  61. Remove PGM-FI main relay 1 (FI MAIN) (A) from the under-dash fuse/relay box.
    Fig 19: Identifying PGM-FI Main Relay 1 (FI MAIN) From Under-Dash Fuse/Relay Box
    G05964524Courtesy of AMERICAN HONDA MOTOR CO., INC.
  62. Measure the voltage between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 4 and body ground.
    Fig 20: Measuring Voltage Between PGM-FI Main Relay 1 (FI MAIN) 4P Connector Terminal No. 4 And Body Ground
    G05964525Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 63.

    NO  -Repair an open in the wire between the No. 8 FI ECU (PCM) (15 A) fuse and PGM-FI main relay 1. If the wire harness is OK, replace the under-dash fuse/relay box (see UNDER-DASH FUSE/RELAY BOX ).

  63. Connect PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 3 to body ground with a jumper wire.
    Fig 21: Connecting PGM-FI Main Relay 1 (FI MAIN) 4P Connector Terminal No. 3 To Body Ground With Jumper Wire
    G05964526Courtesy of AMERICAN HONDA MOTOR CO., INC.
  64. Check for continuity between PCM connector terminal A6 and body ground.
    Fig 22: Checking Continuity Between PCM Connector Terminal A6 And Body Ground
    G05964527Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Test PGM-FI main relay 1 (FI MAIN) (see POWER RELAY TEST ). If the relay is OK, update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). ■

    NO  -Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the PCM (A6). ■

  65. Reconnect PCM connector A (49P).
  66. Turn the ignition switch to ON (II).
  67. Measure the voltage between PCM connector terminal B3 and body ground.
    Fig 23: Measuring Voltage Between Body Ground And PCM Connector Terminal B3
    G00512319Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step  74.

    NO  -Go to step 68.

  68. Turn the ignition switch to LOCK (0).
  69. Remove PGM-FI main relay 1 (FI MAIN) (A) from the under-dash fuse/relay box.
    Fig 24: Identifying PGM-FI Main Relay 1 (FI MAIN) From Under-Dash Fuse/Relay Box
    G05964529Courtesy of AMERICAN HONDA MOTOR CO., INC.
  70. Turn the ignition switch to ON (II).
  71. Measure the voltage between PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 1 and body ground.
    Fig 25: Measuring Voltage Between PGM-FI Main Relay 1 (FI MAIN) 4P Connector Terminal No. 1 And Body Ground
    G05964530Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 72.

    NO  -Repair an open in the wire between the No. 8 FI ECU (PCM) (15 A) fuse and PGM-FI main relay 1.If the wire harness is OK, replace the under-dash fuse/relay box (see UNDER-DASH FUSE/RELAY BOX ).

  72. Turn the ignition switch to LOCK (0).
  73. Connect PGM-FI main relay 1 (FI MAIN) 4P connector terminal No. 2 to body ground with a jumper wire.
    Fig 26: Connecting PGM-FI Main Relay 1 (FI MAIN) 4P Connector Terminal No. 2 To Body Ground With Jumper Wire
    G05964531Courtesy of AMERICAN HONDA MOTOR CO., INC.
  74. Check for continuity between PCM connector terminal B3 and body ground.
    Fig 27: Checking Continuity Between PCM Connector Terminal B3 And Body Ground
    G00512320Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 75.

    NO  -Repair open in the wire between PGM-FI main relay 1 (FI MAIN) and the PCM (B3). ■

  75. Test the PGM-FI main relay 1 (see POWER RELAY TEST ).

    Is PGM-FI main relay 1 OK? 

    YES  -Go to step 76.

    NO  -Replace PGM-FI main relay 1 (FI MAIN). ■

  76. Disconnect PCM connectors A (49P), B (49P), and C (49P).
  77. Check for continuity between body ground and PCM connector terminals A41, B1, B40, B41, C1, and C41 individually.
    Fig 28: Checking Continuity Between Body Ground And PCM Connector Terminals A41, B1, B40, B41, C1, And C41
    G00512321Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Update the PCM if it does not have the latest software (see PCM UPDATE ), or substitute a known-good PCM (see SUBSTITUTING THE PCM ), then recheck. If the symptom/indication goes away with a known-good PCM, replace the original PCM (see PCM REPLACEMENT ). ■

    NO  -Repair open in the wire(s) between the PCM (A41, B1, B40, B41, C1, C41) and body ground (G101) (see ENGINE WIRE HARNESS ).

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