LEMON Manuals: Even more car manuals for everyone
Home >> Honda >> 2021 >> Pilot Special Edition, AWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> HVAC System - DTC Diagnostics >> DTC Troubleshooting >> DTC B2971 (6)

DTC B2971 (6)

DTC B2971 or DTC indicator 6  : A Problem in the Mode Control Motor A Circuit, Linkage, Door, or Motor (Front)

DTC Description DTC
B2971 A problem in the mode control motor A circuit, linkage, door, or motor (front)  

DTCs (AC)

  1. Problem verification

    - 1. Clear the DTCs 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
    B2971 A problem in the mode control motor A circuit, linkage, door, or motor (front)  

    Is DTC B2971 or 6 indicated?

    YES 

    Go to step 2.

    NO 

    Intermittent failure. Check for loose wires or poor connections on the mode control motor A circuit.

  2. Open wire check (MDEF FR line)

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

    - 2. Disconnect the following connectors.

    HVAC control unit connector A (32P)
    Mode control motor A 7P connector

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

    Test condition Vehicle OFF (LOCK) mode
    HVAC control unit connector A (32P): disconnected
    Mode control motor A 7P connector: disconnected
    Test point 1 HVAC control unit connector A (32P) No. 11
    Test point 2 Mode control motor A 7P connector No. 6
    GHH310131Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The MDEF FR wire is not open. Go to step 3.

    NO 

    Repair an open in the wire between the HVAC control unit and the mode control motor A.

  3. Open wire check (MVENT FR line)

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

    Test condition Vehicle OFF (LOCK) mode
    HVAC control unit connector A (32P): disconnected
    Mode control motor A 7P connector: disconnected
    Test point 1 HVAC control unit connector A (32P) No. 12
    Test point 2 Mode control motor A 7P connector No. 7
    GHH310132Courtesy of HONDA, U.S.A., INC.

    Is there continuity?

    YES 

    The MVENT FR wire is not open. Go to step 4.

    NO 

    Repair an open in the wire between the HVAC control unit and the mode control motor A.

  4. Shorted wire check (MDEF FR line)

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

    Test condition Vehicle OFF (LOCK) mode
    HVAC control unit connector A (32P): disconnected
    Mode control motor A 7P connector: disconnected
    Test point 1 HVAC control unit connector A (32P) No. 11
    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 mode control motor A.

    NO 

    The MDEF FR wire is OK. Go to step 5.

  5. Shorted wire check (MVENT FR line)

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

    Test condition Vehicle OFF (LOCK) mode
    HVAC control unit connector A (32P): disconnected
    Mode control motor A 7P connector: disconnected
    Test point 1 HVAC control unit connector A (32P) No. 12
    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 mode control motor A.

    NO 

    The MVENT FR wire is OK. Go to step 6.

  6. Mode control motor A check

    - 1. Test the mode control motor A.

    Is the mode control motor A OK?

    YES 

    Replace the HVAC control unit .

    NO 

    Replace the mode control motor A , or repair the mode control linkage or door.