DTC Troubleshooting: B1641

DTC B1641  : RF2 antenna not connected or malfunction

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.

   One-Push - KEYLESS ACCESS CONTROL UNIT - SELF CHECK

   Do the SELF CHECK.

   -4. Check for DTCs with the HDS.

   DTC Description	DTC
   B1641 RF2 antenna not connected or malfunction

   Is DTC B1641 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 (RF VCC1, RF DATA1, RF GND lines)

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

   -2. Disconnect the following connectors.

   Body control module connector F (36P)

   RF unit 3P 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 RF unit 3P connector: disconnected
   Test point 1	Body control module connector F (36P) No. 24
   Test point 2	Body ground

   Test point 1	Body control module connector F (36P) No. 19
   Test point 2	Body ground

   Test point 1	Body control module connector F (36P) No. 26
   Test point 2	Body ground

   Is there continuity?

   YES 

   Repair a short to ground in the wire.

   NO 

   The RF VCC1, RF DATA1, and RF GND wires are not shorted. Go to step 3.

3. Open wire check (RF VCC1, RF DATA1, RF GND lines)

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

   Test condition	Vehicle OFF (LOCK) mode Body control module connector F (36P): disconnected RF unit 3P connector: disconnected
   Test point 1	Body control module connector F (36P) No. 24
   Test point 2	RF unit 3P connector (female terminals) No. 3:

   Test point 1	Body control module connector F (36P) No. 19
   Test point 2	RF unit 3P connector (female terminals) No. 2:

   Test point 1	Body control module connector F (36P) No. 26
   Test point 2	RF unit 3P connector (female terminals) No. 1:

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

   Is there continuity?

   YES 

   The RF VCC1, RF DATA1, and RF GND wires are OK. Go to step 4.

   NO 

   Repair an open or high resistance in the wire.

4. Body control module RF VCC1 line output check

   -1. Reconnect the body control module connector F (36P).

   -2. Connect the voltmeter between test points 1 and 2.

   Test point 1	RF unit 3P connector (female terminals) No. 3:
   Test point 2	Body ground

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

   -3. Select the KEYLESS ACCESS CONTROL UNIT from the ONE-PUSH START system select menu with the HDS, and enter the FUNCTIONAL TESTS, and do the RF2 RXVCC DRIVING.

   One-Push - KEYLESS ACCESS CONTROL UNIT - FUNCTIONAL TESTS

   the voltage change from 0 to 5 V?

   YES 

   Check for loose or poor connection. If the connection is OK, replace the RF unit .

   NO 

   Check for loose or poor connection. If the connection is OK, replace the body control module .