DTC B1241 (9) (HVAC Control Unit)

DTC B1241 or indicator 9  : A problem in the blower motor circuit (front)

DTCs (AC)

1. Problem verification

   -1. Clear the DTC with the HDS.

   -2. Turn the vehicle to the OFF (LOCK) mode, then the ON mode.

   -3. Do the Self-Diagnostic Function with the HDS or the HVAC control unit .

   -4. Check for DTCs.

   DTC Description	DTC
   B1241 A problem in the blower motor circuit (front)

   Is DTC B1241 or 9 indicated?

   YES 

   Go to step 2.

   NO 

   Intermittent failure. Check for loose wires or poor connections on the front blower motor circuit.

2. Fuse check

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Check the following fuse.

   Fuse	No. A2-6 (40 A)
   Location	Under-hood fuse/relay box

   Is the fuse OK?

   YES 

   Go to step 3.

   NO 

   Replace the fuse, and recheck. If the fuse blows again, repair a short in the No. A2-6 (40 A) fuse circuit.

3. Front blower motor power circuit check (FR BLOWER MTR+ line)

   -1. Disconnect the following connector.

   Front blower motor 2P connector

   -2. Turn the vehicle to the ON mode.

   -3. Measure the voltage between test points 1 and 2.

   Test condition	Vehicle ON mode
   	Front blower motor 2P connector: disconnected
   Test point 1	Front blower motor 2P connector (female terminals) No. 2:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there battery voltage?

   YES 

   Go to step 4.

   NO 

   Go to step  12.

4. Front blower motor operation check (FR BLOWER MTR- line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Reconnect the front blower motor 2P connector.

   -3. Connect terminals A and B with a jumper wire.

   Terminal A	Front blower motor 2P connector (female terminals) No. 1:
   Terminal B	Body ground

   Courtesy of HONDA, U.S.A., INC.

   -4. Turn the vehicle to the ON mode.

   Does the front blower motor run at high speed?

   YES 

   Go to step 5.

   NO 

   Replace the front blower motor .

5. Open wire check (GND line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the jumper wire.

   -3. Disconnect the following connector.

   Front power transistor 4P connector

   -4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Front power transistor 4P connector: disconnected
   Test point 1	Front power transistor 4P connector (female terminals) No. 3:
   Test point 2	Body ground

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The GND wire is OK. Go to step 6.

   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 G251.

6. Open wire check (FR BLOWER MTR- line)

   -1. Connect terminals A and B with a jumper wire.

   Terminal A	Front power transistor 4P connector (female terminals) No. 3:
   Terminal B	Front power transistor 4P connector (female terminals) No. 4:

   Courtesy of HONDA, U.S.A., INC.

   -2. Turn the vehicle to the ON mode.

   Does the front blower motor run at high speed?

   YES 

   The FR BLOWER MTR- wire is OK. Go to step 7.

   NO 

   Repair an open in the wire between the front power transistor and the front blower motor.

7. Shorted wire check (BLOWER (V) line)

   -1. Turn the vehicle to the OFF (LOCK) mode.

   -2. Disconnect the jumper wire.

   -3. Disconnect the following connector.

   HVAC control unit connector A (32P)

   -4. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	HVAC control unit connector A (32P): disconnected
   	Front power transistor 4P connector: disconnected
   Test point 1	HVAC control unit connector A (32P) No. 31
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to body ground in the wire between the HVAC control unit and the front power transistor.

   NO 

   The BLOWER (V) wire is not shorted. Go to step 8.

8. Shorted wire check (BLOWER (G) line)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	HVAC control unit connector A (32P): disconnected
   	Front power transistor 4P connector: disconnected
   Test point 1	HVAC control unit connector A (32P) No. 32
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to body ground in the wire between the HVAC control unit and the front power transistor.

   NO 

   The BLOWER (G) wire is not shorted. Go to step 9.

9. Open wire check (BLOWER (G) line)

   -1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	HVAC control unit connector A (32P): disconnected
   	Front power transistor 4P connector: disconnected
   Test point 1	HVAC control unit connector A (32P) No. 32
   Test point 2	Front power transistor 4P connector (female terminals) No. 1:

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The BLOWER (G) wire is OK. Go to step 10.

   NO 

   Repair an open in the wire between the HVAC control unit and the front power transistor.

10. Open wire check (BLOWER (V) line)

    -1. Check for continuity between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	HVAC control unit connector A (32P): disconnected
    	Front power transistor 4P connector: disconnected
    Test point 1	HVAC control unit connector A (32P) No. 31
    Test point 2	Front power transistor 4P connector (female terminals) No. 2:

    Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The BLOWER (V) wire is OK. Go to step 11.

    NO 

    Repair an open in the wire between the HVAC control unit and the front power transistor.

11. Front power transistor check

    -1. Test the front power transistor .

    Is the front power transistor OK?

    YES 

    Replace the HVAC control unit .

    NO 

    Replace the front power transistor .

    NOTE: If the front power transistor is faulty, check the front blower motor for damage. If necessary, replace the front blower motor .
12. Front blower motor relay check

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Remove the front blower motor relay from the relay holder L, and test it .

    Is the relay OK?

    YES 

    Go to step 13.

    NO 

    Replace the front blower motor relay.

13. Open wire check (+B FR BLOWER line)

    -1. Measure the voltage between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Front blower motor relay: disconnected
    Test point 1	Front blower motor relay 4P socket (female terminals) No. 1:
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The +B FR BLOWER wire is OK. Go to step 14.

    NO 

    Repair an open in the wire between the No. A2-6 (40 A) fuse in the under-hood fuse/relay box and the front blower motor relay. If the wire is OK, replace the under-hood fuse/relay box .

14. Open wire check (IG2 A/C line)

    -1. Turn the vehicle to the ON mode.

    -2. Measure the voltage between test points 1 and 2.

    Test condition	Vehicle ON mode
    	Front blower motor relay: disconnected
    Test point 1	Front blower motor relay 4P socket (female terminals) No. 3:
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there battery voltage?

    YES 

    The IG2 A/C wire is OK. Go to step 15.

    NO 

    Repair an open in the wire between the No. C23 (7.5 A) fuse in the under-dash fuse/relay box and the front blower motor relay.

15. Open wire check (GND line)

    -1. Turn the vehicle to the OFF (LOCK) mode.

    -2. Check for continuity between test points 1 and 2.

    Test condition	Vehicle OFF (LOCK) mode
    	Front blower motor relay: disconnected
    Test point 1	Front blower motor relay 4P socket (female terminals) No. 4:
    Test point 2	Body ground

    Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    Repair an open in the wire between the front blower motor relay and the front blower motor.

    NO 

    Check for an open in the wire between the front blower motor relay and body ground. If the wire is OK, check for poor ground at G405.