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Home >> Honda >> 2013 >> CR-Z Base, Automatic CVT Trans >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Climate Control >> DTC Troubleshooting >> DTC B1241 or DTC indicator F and A/C: A Problem in the Blower Motor Circuit

DTC B1241 or DTC indicator F and A/C: A Problem in the Blower Motor Circuit

  1. Clear the DTC with the HDS.
  2. Turn the ignition switch to LOCK (0), and then 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 climate control unit (see HOW TO USE THE SELF-DIAGNOSTIC FUNCTION WITHOUT THE HDS  ).
  4. Check for DTCs.

    Is DTC B1241 or F and A/C indicated? 

    YES  -Go to step  5.

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

  5. Turn the ignition switch to LOCK (0).
  6. Check the No. B10 (7.5 A) and No. B57 (30 A) fuses in the under-dash fuse/relay box.

    Are the fuses OK? 

    YES  -Go to step  7.

    NO  -Replace the fuse(s), and recheck. If fuse(s) blow again, check for a short in the No. B10 (7.5 A) and No. B57 (30 A) fuses circuit.

  7. Disconnect the blower motor 2P connector.
  8. Turn the ignition switch to ON (II).
  9. Measure the voltage between blower motor 2P connector terminal No. 2 and body ground.
    Fig 1: Measuring Voltage Between Blower Motor 2P Connector Terminal No. 2 And Body Ground
    G06953646Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step  10.

    NO  -Go to step  30.

  10. Turn the ignition switch to LOCK (0).
  11. Reconnect the blower motor 2P connector.
  12. Connect blower motor 2P connector terminal No. 1 to body ground with a jumper wire.
    Fig 2: Connecting Blower Motor 2P Connector Terminal No. 1 To Body Ground With Jumper Wire
    G06953647Courtesy of AMERICAN HONDA MOTOR CO., INC.
  13. Turn the ignition switch to ON (II).

    Does the blower motor run? 

    YES  -Go to step  14.

    NO  -Replace the blower motor (see BLOWER UNIT COMPONENT REPLACEMENT  ).

  14. Turn the ignition switch to LOCK (0).
  15. Disconnect the jumper wire.
  16. Disconnect the power transistor 4P connector.
  17. Check for continuity between power transistor 4P connector terminal No. 1 and body ground.
    Fig 3: Checking Continuity Between Power Transistor 4P Connector Terminal No. 1 And Body Ground
    G06953648Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step  18.

    NO  -Check for an open in the BLK wire between the power transistor and body ground. If the wire is OK, check for poor body ground at G502 (see DASHBOARD WIRE HARNESS (VIEW OF MIDDLE SECTION) (BD) ).

  18. Connect power transistor 4P connector terminals No. 1 and No. 3 with a jumper wire.
    Fig 4: Connecting Power Transistor 4P Connector Terminals No. 1 And No. 3 With Jumper Wire
    G06953649Courtesy of AMERICAN HONDA MOTOR CO., INC.
  19. Turn the ignition switch to ON (II).

    Does the blower motor run at high speed? 

    YES  -Go to step  20.

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

  20. Turn the ignition switch to LOCK (0).
  21. Disconnect the jumper wire.
  22. Disconnect the climate control unit 36P connector.
  23. Check for continuity between body ground and climate control unit 36P connector terminals No. 5 and No. 6 individually.
    Fig 5: Checking Continuity Between Body Ground And Climate Control Unit 36P Connector Terminals No. 5 And No. 6
    G06953650Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

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

    NO  -Go to step  24.

  24. Check for continuity between the following terminals of the climate control unit 36P connector and the power transistor 4P connector.

    36P: 4P:

    No. 5 No. 4

    No. 6 No. 2

    Fig 6: Checking Continuity Between Climate Control Unit 36P Connector Terminals And Power Transistor 4P Connector Terminals
    G06953651Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step  25.

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

  25. Turn the ignition switch to ON (II).
  26. Measure the voltage between body ground and climate control unit 36P connector terminals No. 5 and No. 6 individually.
    Fig 7: Measuring Voltage Between Body Ground And Climate Control Unit 36P Connector Terminals No. 5 And No. 6
    G06953652Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there voltage? 

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

    NO  -Go to step  27.

  27. Turn the ignition switch to LOCK (0).
  28. Reconnect the climate control unit 36P connector.
  29. Test the power transistor (see SUNLIGHT SENSOR TEST  ).

    Is the power transistor OK? 

    YES  -Check for loose wires or poor connections at the climate control unit 36P connector and at the power transistor 4P connector. If the connections are good, substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original climate control unit (see CLIMATE CONTROL UNIT REMOVAL/INSTALLATION  ).

    NO  -Replace the power transistor (see SUNLIGHT SENSOR TEST  ).

    NOTE: If the power transistor is faulty, check the blower motor for damage. If necessary, replace the blower motor (see BLOWER UNIT COMPONENT REPLACEMENT  ).
  30. Turn the ignition switch to LOCK (0).
  31. Remove the blower motor relay from the under-dash fuse/relay box, and test it (see POWER RELAY TEST ).

    Is the relay OK? 

    YES  -Go to step  32.

    NO  -Replace the blower motor relay.

  32. Measure the voltage between blower motor relay 4P socket terminal No. 1 and body ground.
    Fig 8: Measuring Voltage Between Blower Motor Relay 4P Socket Terminal No. 1 And Body Ground
    G06953653Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step  33.

    NO  -Replace the under-dash fuse/relay box.

  33. Turn the ignition switch to ON (II).
  34. Measure the voltage between blower motor relay 4P socket terminal No. 3 and body ground.
    Fig 9: Measuring Voltage Between Blower Motor Relay 4P Socket Terminal No. 3 And Body Ground
    G06953654Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step  35.

    NO  -Replace the under-dash fuse/relay box.

  35. Turn the ignition switch to LOCK (0).
  36. Check for continuity between blower motor relay 4P socket terminal No. 4 and body ground.
    Fig 10: Checking Continuity Between Blower Motor Relay 4P Socket Terminal No. 4 And Body Ground
    G06953655Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair an open in the WHT wire between the blower motor relay and the blower motor.

    NO  -Check for an open in the wire between the blower motor relay and body ground. If the wire is OK, check for poor ground at G501 (see VISOR SWITCH SUBHARNESS (BE) ).