DTC Troubleshooting: B2A70-12
DTC B2A70-12: LDW/RDM Switch Signal Circuit Short
NOTE: Before you troubleshoot, review the general troubleshooting information.

DTC Description
DTC
Freeze Frame
B2A70-12 LDW/RDM Switch Signal Circuit Short
    

1.
Problem verification:

Problem verification
?1.
Turn the vehicle to the ON mode.

?2.
Clear the DTC with the HDS.


?3.
Turn the vehicle to the OFF (LOCK) mode, then the ON mode.

?4.
Press the RDM switch.

?5.
Check for DTCs with the HDS.
DTC Description
DTC
Freeze Frame
B2A70-12 LDW/RDM Switch Signal Circuit Short
    

Is DTC B2A70-12 indicated?

     
YES
     
     
     
The failure is duplicated. Go to step 2.
     
NO
     
     
     
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.?
2.
Fuse check:

Fuse check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Check the following fuse.
Fuse
No. C39

Is the fuse OK?

     
YES
     
     
     
The fuse is OK. Reinstall the fuse, then go to step 3.
     
NO
     
     
     
Replace the fuse. Turn the vehicle to the ON mode, then the OFF (LOCK) mode. If the fuse blows again, repair the short to ground on the No. C39 fuse circuit.?
3.
Open wire check (IG1 OPTION line):

Open wire check (IG1 OPTION line)
?1.
Disconnect the following connector.
CMBS OFF switch/RDM switch 10P connector

?2.
Turn the vehicle to the ON mode.

?3.
Measure the voltage between test points 1 and 2.
Test condition
Vehicle ON mode
 
CMBS OFF switch/RDM switch 10P connector: disconnected
Test point 1
CMBS OFF switch/RDM switch 10P connector (female terminals) No. 11:
Test point 2
Body ground


Is there battery voltage?

     
YES
     
     
     
IG1 OPTION wire is OK. Go to step 4.
     
NO
     
     
     
Repair an open in the IG1 OPTION wire between the RDM switch and No. C39 fuse in the under-dash fuse/relay box.?
4.
RDM switch internal resistance check:

RDM switch internal resistance check
?1.
Turn the vehicle to the OFF (LOCK) mode.

?2.
Remove and test the RDM switch.

Is the RDM switch OK?

     
YES
     
     
     
RDM switch is OK. Go to step 5.
     
NO
     
     
     
5.
Open wire check (LDW OFF SW line):

Open wire check (LDW OFF SW line)
?1.
Install the RDM switch.

?2.
Connect the following connector.
CMBS OFF switch/RDM switch 10P connector

?3.
Disconnect the following connector.
Multipurpose camera unit 20P connector

?4.
Turn the vehicle to the ON mode.

?5.
Check for continuity between test points 1 and 2.
Test condition
Vehicle ON mode
 
Multipurpose camera unit 20P connector: disconnected
Test point 1
Multipurpose camera unit 20P connector No. 8
Test point 2
Body ground

?6.
Press the RDM switch.

Is there battery voltage?

     
YES
     
     
     
Check for loose terminals and poor connections in the multipurpose camera unit 20P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the multipurpose camera unit.?
     
NO
     
     
     
Repair an open in the LDW OFF SW wire between the RDM switch and the multipurpose camera unit.?