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 (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 F (36P)Right-front LF antenna/initiator 2P connector

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

   Test condition	Vehicle OFF (LOCK) mode Body control module connector F (36P): disconnected Right-front LF antenna/initiator 2P connector: disconnected
   Test point 1	Body control module connector F (36P) No. 12
   Test point 2	Body ground

   Test point 1	Body control module connector F (36P) No. 30
   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 F (36P): disconnected Right-front LF antenna/initiator 2P connector: disconnected
   Test point 1	Body control module connector F (36P) No. 12
   Test point 2	Body control module connector F (36P) No. 30

   Is there continuity?

   YES 

   Repair a short in EXT FR AS+ to EXT FR AS- wire.

   NO 

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

4. EXT FR AS+, EXT FR AS- line output check

   -1. Reconnect the following connector.

   Body control module connector F (36P)

   -2. Turn the vehicle to the ON mode.

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

   Test condition	Vehicle ON mode Right-front LF antenna/initiator 2P connector: disconnected
   Test point 1	Right-front LF antenna/initiator 2P connector (female terminals) No. 1:
   Test point 2	Right-front LF antenna/initiator 2P connector (female terminals) No. 2:

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

   Is there voltage?

   YES 

   Replace the right-front LF antenna/initiator .

   NO 

   Replace the body control module (Keyless Access Control Unit) .