DTC Troubleshooting: B1657
DTC B1657: Rear Bumper 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
B1657 Rear Bumper LF Antenna Circuit Short
  

1.
Problem verification:

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.

?4.
Check for DTCs with the HDS.
DTC Description
DTC
B1657 Rear Bumper LF Antenna Circuit Short
  

Is DTC B1657 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 TR+, EXT TR- lines):

Shorted wire check (EXT TR+, EXT TR- lines)
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Disconnect the following connectors.
Body control module connector F (36P)
Rear bumper LF antenna 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
Rear bumper LF antenna 2P connector: disconnected
Test point 1
Body control module connector F (36P) No. 32
Test point 2
Body ground

Test point 1
Body control module connector F (36P) No. 14
Test point 2
Body ground

Is there continuity?

     
YES
     
     
     
Repair a short to ground in the wire.?
     
NO
     
     
     
The EXT TR+ and EXT TR- wires are not shorted. Go to step 3.
3.
Shorted wire check (EXT TR+ to EXT TR- line):

Shorted wire check (EXT TR+ to EXT TR- line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
Body control module connector F (36P): disconnected
Rear bumper LF antenna 2P connector: disconnected
Test point 1
Body control module connector F (36P) No. 32
Test point 2
Body control module connector F (36P) No. 14

Is there continuity?

     
YES
     
     
     
Repair a short in EXT TR+ to EXT TR- wire.?
     
NO
     
     
     
The EXT TR+ and EXT TR- wires are OK. Go to step 4.
4.
EXT TR+, EXT TR- line output check:

EXT TR+, EXT TR- 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
Rear bumper LF antenna 2P connector: disconnected
Test point 1
Rear bumper LF antenna 2P connector No. 1
Test point 2
Rear bumper LF antenna 2P connector No. 2


Is there voltage?

     
YES
     
     
     
Faulty rear bumper LF antenna; replace the rear bumper LF antenna.?
     
NO