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Home >> Chevrolet >> 2010 >> Cobalt LS, 4D Sedan, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 15 (Heating, Ventilation And Air Conditioning) >> 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

WARNING: This page is about a different car, the 2011 Honda Insight and 2010 Honda Insight. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: A problem in the blower motor circuit can cause the A/C to be inoperative.
  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 in the blower motor circuit.

  5. Turn the ignition switch to LOCK (0).
  6. Check the No. 10 (7.5 A) and No. 57 (30 A) fuses in the under-dash fuse/relay box.

    Are the fuses OK? 

    YES  -Go to step 7.

    NO  -Replace the fuses, and recheck. If fuses blow again, check for a short in the No. 10 (7.5 A) and No. 57 (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. 1 and body ground.
    Fig 1: Measuring Voltage Between Blower Motor 2P Connector Terminal No. 1 And Body Ground
    G00500477Courtesy 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. 2 to body ground with a jumper wire.
    Fig 2: Connecting Blower Motor 2P Connector Terminal No. 2 To Body Ground With Jumper Wire
    G06431302Courtesy 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. 2 and body ground.
    Fig 3: Checking Continuity Between Power Transistor 4P Connector Terminal No. 2 And Body Ground
    G06431303Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 18.

    NO  -Check for an open in the wire between the power transistor and body ground. If the wire is OK, check for poor body ground at G502.

  18. Connect power transistor 4P connector terminals No. 2 and No. 4 with a jumper wire.
    Fig 4: Connecting Power Transistor 4P Connector Terminals No. 2 And No. 4 With Jumper Wire
    G06431304Courtesy 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. 15 and No. 34 individually.
    Fig 5: Checking Continuity Between Body Ground And Climate Control Unit 36P Connector Terminals No. 15 And No. 34
    G06431305Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Repair a short to body ground in the wires 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. 15 No. 3
    No. 34 No. 1
    Fig 6: Checking Continuity Between Climate Control Unit 36P Connector And Power Transistor 4P Connector
    G06431306Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there continuity? 

    YES  -Go to step 25.

    NO  -Repair an open in the wires 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. 15 and No. 34 individually.
    Fig 7: Measuring Voltage Between Body Ground And Climate Control Unit 36P Connector Terminals No. 15 And No. 34
    G06431307Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there voltage? 

    YES  -Repair a short to power in the wires.

    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 REPLACEMENT ).

    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.

    NO  -Replace the power transistor (see ).

    NOTE: If the power transistor is faulty, check the blower motor for damage. If necessary, replace the blower motor.
  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
    G06431309Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 33.

    NO  -Replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).

  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
    G06431310Courtesy of AMERICAN HONDA MOTOR CO., INC.

    Is there battery voltage? 

    YES  -Go to step 35.

    NO  -Replace the under-dash fuse/relay box (see REMOVAL AND INSTALLATION ).

  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
    G06431311Courtesy 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 open in the wire between the blower motor relay and body ground. If the wire is OK, check for poor ground at G501.

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