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DTC B1647

DTC B1647  : Passenger's Door LF Antenna Circuit Short

NOTE:  If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A .

DTC Description DTC
B1647 Passenger's Door LF Antenna Circuit Short  

DTC (Keyless Access Control Unit)

  1. Problem verification

    -1. Clear the DTCs with the HDS.

    -2. Select the KEYLESS ACCESS CONTROL UNIT from the ONE-PUSH START system select menu with the HDS, and enter the SELF CHECK.

    -3. Do the SELF CHECK.

    SELF CHECK

    Check for DTCs with the HDS.

    DTC Description DTC
    B1647 Passenger's Door LF Antenna Circuit Short  

    Is DTC B1647 indicated?

    YES 

    Go to step 2.

    NO 

    Intermittent failure, the system is OK at this time. Check for loose or poor connections.

  2. Shorted wire check (EXT FR AS+, EXT FR AS- lines)

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

    -2. Disconnect the following connectors.

    Body control module connector C (66P)Front passenger's door outer handle 8P connector

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

    Test condition Vehicle OFF (LOCK) mode
    Body control module connector C (66P): disconnected
    Front passenger's door outer handle 8P connector: disconnected
    Test point 1 Body control module connector C (66P) No. 49
    Test point 2 Body ground
    Test point 1 Body control module connector C (66P) No. 65
    Test point 2 Body ground

    Is there continuity?

    YES 

    Repair a short to ground in the wire.

    NO 

    The EXT FR AS+ and EXT FR AS- wires are not shorted. Go to step 3.

  3. Shorted wire check (EXT FR AS+ to EXT FR AS- line)

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

    Test condition Vehicle OFF (LOCK) mode
    Body control module connector C (66P): disconnected
    Front passenger's door outer handle 8P connector: disconnected
    Test point 1 Body control module connector C (66P) No. 49
    Test point 2 Body control module connector C (66P) No. 65

    Is there continuity?

    YES 

    Repair a short to ground in the wire.

    NO 

    The EXT FR AS+ and EXT FR AS- wires are OK. Go to step 4.

  4. Front passenger's door outer handle LF antenna internal resistance check

    -1. On the LF antenna side, measure the resistance between test points 1 and 2.

    Test condition Vehicle OFF (LOCK) mode
    Body control module connector C (66P): disconnected
    Front passenger's door outer handle 8P connector: disconnected
    Test point 1 Front passenger's door outer handle 8P connector (male terminals) No. 2:
    Test point 2 Front passenger's door outer handle 8P connector (male terminals) No. 6:
    GHH387050Courtesy of HONDA, U.S.A., INC.

    Is there overrange?

    YES 

    Replace the body control module .

    NO 

    Faulty LF antenna; replace the front passenger's door outer handle .