DTC B1649

WARNING: This page does not describe the selected car, but rather 11 other vehicles, including the 2025 Honda Odyssey, 2024 Honda Odyssey, 2023 Honda Odyssey, 2022 Honda Odyssey, and 2021 Honda Odyssey. However, it is still accessible from the selected car via links, so may be relevant.

DTC B1649 : Driver Side Rear Passenger Door 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
B1649 Driver Side Rear Passenger Door Antenna Circuit Short

DTC (Keyless Access Control Unit)

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
B1649 Driver Side Rear Passenger Door Antenna Circuit Short

Is DTC B1649 indicated?

YES

Go to step 2.

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

Shorted wire check (EXT RR L+, EXT RR L- lines)

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

-2. Disconnect the following connectors.

Body control module connector F (36P)Left-rear 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 Left-rear LF antenna/initiator 2P connector: disconnected
Test point 1	Body control module connector F (36P) No. 16
Test point 2	Body ground

Test point 1	Body control module connector F (36P) No. 34
Test point 2	Body ground

Is there continuity?

YES

Repair a short to ground in the wire.

The EXT RR L+ and EXT RR L- wires are not shorted. Go to step 3.

Shorted wire check (EXT RR L+ to EXT RR L- line)

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

Test condition	Vehicle OFF (LOCK) mode Body control module connector F (36P): disconnected Left-rear LF antenna/initiator 2P connector: disconnected
Test point 1	Body control module connector F (36P) No. 16
Test point 2	Body control module connector F (36P) No. 34

Is there continuity?

YES

Repair a short in EXT RR L+ to EXT RR L- wire.

The EXT RR L+ and EXT RR L- wires are OK. Go to step 4.

EXT RR L+, EXT RR L- 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 Left-rear LF antenna/initiator 2P connector: disconnected
Test point 1	Left-rear LF antenna/initiator 2P connector (female terminals) No. 1:
Test point 2	Left-rear LF antenna/initiator 2P connector (female terminals) No. 2:

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

Is there voltage?

YES

Replace the left-rear LF antenna/initiator .

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