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Home >> Honda >> 2016 >> Odyssey EX >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heating/Air Conditioning >> DTC Troubleshooting >> DTC B1241 or DTC indicator 1: A Problem in the Blower Motor Circuit (Front)

DTC B1241 or DTC indicator 1: A Problem in the Blower Motor Circuit (Front)

  1. Clear the DTCs with the HDS.
  2. Turn the ignition switch to LOCK (0), and then back to ON (II).
  3. Do the Self-Diagnostic Function with the HDS (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITH THE HDS  ) or the HVAC control unit (see HOW TO USE THE HVAC CONTROL UNIT SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS  ).
  4. Check for DTCs.

    Is DTC B1241 or 1 indicated? 

    YES  -Go to step 5.

    NO  -Intermittent failure. Check for loose wires or poor connections in the front blower motor circuit.

  5. Turn the ignition switch to LOCK (0).
  6. Check the No. A3-7 (40 A) fuse in the main under-hood fuse box, and the No. C26 (7.5 A) fuse in the driver's under-dash fuse/relay box.

    Are the fuses OK? 

    YES  -Go to step 7.

    NO  -Replace the fuse(s), and recheck. If the fuse(s) blow again, check for a short in the No. A3-7 (40 A) fuse and No. C26 (7.5 A) fuse circuits.

  7. Connect front blower motor 2P connector terminal No. 1 to body ground with a jumper wire.
    Fig 1: Identifying Jumper Wire Connection Between Front Blower Motor 2P Connector Terminal No. 1 And Body Ground
    G06968133Courtesy of AMERICAN HONDA MOTOR CO., INC.
  8. Turn the ignition switch to ON (II).

    Does the front blower motor run at high speed? 

    YES  -Go to step 9.

    NO  -Go to step  25.

  9. Turn the ignition switch to LOCK (0).
  10. Disconnect the jumper wire.
  11. Disconnect the front power transistor 5P connector.
  12. Check for continuity between front power transistor 5P connector terminal No. 4 and body ground.
    Fig 2: Checking Continuity Between Front Power Transistor 5P Connector Terminal No. 4 And Body Ground
    G06968134Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 13.

    NO  -Check for an open in the wire between the front power transistor and body ground. If the wire is OK, check for poor ground at G204 (see RIGHT ENGINE COMPARTMENT WIRE HARNESS (DASHBOARD BRANCH) (F) ).

  13. Connect front power transistor 5P connector terminals No. 4 and No. 5 with a jumper wire.
    Fig 3: Identifying Jumper Wire Connection Between Front Power Transistor 5P Connector Terminal No. 5 And Body Ground
    G06968135Courtesy of AMERICAN HONDA MOTOR CO., INC.
  14. Turn the ignition switch to ON (II).

    Does the front blower motor run at high speed? 

    YES  -Go to step 15.

    NO  -Repair an open in the GRN wire between the front power transistor and the front blower motor.

  15. Turn the ignition switch to LOCK (0).
  16. Disconnect the jumper wire.
  17. Disconnect the HVAC control unit 28P connector.
  18. Check for continuity between body ground and HVAC control unit 28P connector terminals No. 9 and No. 10 individually.
    Fig 4: Checking Continuity Between Body Ground And HVAC Control Unit 28P Connector Terminals No. 9 And No. 10
    G06968136Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to body ground in the wire(s) between the HVAC control unit and the front power transistor.

    NO  -Go to step 19.

  19. Check for continuity between the following terminals of the HVAC control unit 28P connector and the front power transistor 5P connector.
    CONNECTOR TERMINAL REFERENCE CHART

    28P: 5P:
    No. 9 No. 3
    No. 10 No. 1
    Fig 5: Checking Continuity Between HVAC Control Unit 28P Connector And Front Power Transistor 5P Connector Terminals
    G06968137Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 20.

    NO  -Repair an open in the wire(s) between the HVAC control unit and the front power transistor.

  20. Turn the ignition switch to ON (II).
  21. Measure the voltage between body ground and HVAC control unit 28P connector terminals No. 9 and No. 10 individually.
    Fig 6: Measuring Voltage Between Body Ground And HVAC Control Unit 28P Connector Terminals No. 9 And No. 10
    G06968138Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there any voltage? 

    YES  -Repair a short to power in the wire(s).

    NO  -Go to step 22.

  22. Turn the ignition switch to LOCK (0).
  23. Reconnect the HVAC control unit 28P connector.
  24. Test the front power transistor (see FRONT POWER TRANSISTOR TEST  ).

    Is the front power transistor OK? 

    YES  -Check for loose wires or poor connections at the HVAC control unit 28P connector and at the front power transistor 5P connector. If the connections are good, substitute a known-good HVAC control unit, and recheck. If the symptom/indication goes away, replace the original HVAC control unit (see HVAC CONTROL UNIT REMOVAL/INSTALLATION  ).

    NO  -Replace the front power transistor (see FRONT POWER TRANSISTOR TEST  ).

    NOTE: If the front power transistor is faulty, check the front blower motor for damage. If necessary, replace the front blower motor.
  25. Turn the ignition switch to LOCK (0).
  26. Disconnect the jumper wire.
  27. Disconnect the front blower motor 2P connector.
  28. Turn the ignition switch to ON (II).
  29. Measure the voltage between front blower motor 2P connector terminal No. 2 and body ground.
    Fig 7: Measuring Voltage Between Front Blower Motor 2P Connector Terminal No. 2 And Body Ground
    G06968139Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Replace the front blower motor (see BLOWER UNIT COMPONENT REPLACEMENT  ).

    NO  -Go to step 30.

  30. Turn the ignition switch to LOCK (0).
  31. Remove the front blower motor relay from the relay block, and test it (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Go to step 32.

    NO  -Replace the front blower motor relay.

  32. Check for continuity between front blower motor relay 4P socket terminal No. 2 and front blower motor 2P connector terminal No. 2.
    Fig 8: Checking Continuity Between Front Blower Motor Relay 4P Socket Terminal No. 2 And Front Blower Motor 2P Connector Terminal No. 2
    G06968140Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 33.

    NO  -Repair an open in the wire between the front blower motor relay and the front blower motor.

  33. Measure the voltage between front blower motor relay 4P socket terminal No. 1 and body ground.
    Fig 9: Measuring Voltage Between Front Blower Motor Relay 4P Socket Terminal No. 1 And Body Ground
    G06968141Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 34.

    NO  -Repair an open in the wire between the relay block and the main under-hood fuse box.

  34. Check for continuity between front blower motor relay 4P socket terminal No. 4 and body ground.
    Fig 10: Checking Continuity Between HVAC Control Unit 28P Connector Terminal No. 22 And Body Ground
    G06968142Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair an open in the wire between the No. C26 (7.5 A) fuse in the driver's under-dash fuse/relay box and the front blower motor relay 4P socket.

    NO  -Check for an open in the wire between blower motor relay 4P socket terminal No. 4 and body ground. If the wire is OK, check for poor ground at G302 (see LEFT ENGINE COMPARTMENT WIRE HARNESS (DASHBOARD BRANCH) (G) ).