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DTC B1645

WARNING: This page is about a different variant/trim than selected.

DTC B1645  : Driver'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
B1645 Driver'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.

    One-Push - KEYLESS ACCESS CONTROL UNIT - SELF CHECK

    -3. Do the SELF CHECK.

    -4. Check for DTCs with the HDS.

    DTC Description DTC
    B1645 Driver's Door LF Antenna Circuit Short  

    Is DTC B1645 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_DR+, EXT_FR_DR- lines)

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

    -2. Disconnect the following connectors.

    Body control module connector F (36P)
    Driver's door outer handle 8P connector

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

    Test condition Vehicle OFF (LOCK) mode
    Body control module connector F (36P): disconnected
    Driver's door outer handle 8P connector: disconnected
    Test point 1 Body control module connector F (36P) No. 13
    Test point 2 Body ground
    Test point 1 Body control module connector F (36P) No. 31
    Test point 2 Body ground

    Is there 1.0 MΩ or more?

    YES 

    The EXT_FR_DR+ and EXT_FR_DR- wires are not shorted. Go to step 3.

    NO 

    Repair a short to ground in the wire.

  3. Shorted wire check (EXT_FR_DR+ line to EXT_FR_DR- line)

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

    Test condition Vehicle OFF (LOCK) mode
    Body control module connector F (36P): disconnected
    Driver's door outer handle 8P connector: disconnected
    Test point 1 Body control module connector F (36P) No. 13
    Test point 2 Body control module connector F (36P) No. 31

    Is there 1.0 MΩ or more?

    YES 

    The EXT_FR_DR+ and EXT_FR_DR- wires are OK. Go to step 4.

    NO 

    Repair a short in EXT_FR_DR+ wire to EXT_FR_DR- wire.

  4. Body control module EXT_FR_DR+, EXT_FR_DR- line output check

    -1. Reconnect the following connector.

    Body control module connector F (36P)

    -2. Turn the vehicle to the ON mode.

    -3. Select KEYLESS ACCESS CONTROL UNIT from the ONE-PUSH START system select menu with the HDS, and enter FUNCTIONAL TESTS.

    One-Push - KEYLESS ACCESS CONTROL UNIT - FUNCTIONAL TESTS

    -4. Measure the voltage between test points 1 and 2.

    Test condition Vehicle ON mode
    Driver's door outer handle 8P connector: disconnected
    Test point 1 Driver's door outer handle 8P connector (female terminals) No. 2:
    Test point 2 Driver's door outer handle 8P connector (female terminals) No. 6:
    GHH379726Courtesy of HONDA, U.S.A., INC.

    -5. Select DRIVER (DOOR) ANTENNA L DC OUTPUT with the HDS.

    Is there voltage?

    YES 

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

    NO 

    Replace the body control module .