DTC Troubleshooting: B2A70-12
DTC B2A70-12: LDW/RDM Switch Signal Circuit Short
NOTE:
Before you troubleshoot, review the general troubleshooting information.
The functions of the integrated driver support system that will be temporarily canceled when this DTC is recorded can be confirmed with the DTC troubleshooting index.

DTC Description
DTC
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.

?4.
Turn the vehicle to the ON mode, then wait for at least 6 seconds.

?5.
Press the RDM switch.

?6.
Check for DTCs with the HDS.
DTC Description
DTC
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.?
2.
Fuse check:

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

?2.
Check the following fuse.
Fuse
No. B5 (10 A)
Location
Under-dash fuse/relay box

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. B5 (10 A) fuse circuit.?
3.
Open wire check (IG1 OPTION line):

Open wire check (IG1 OPTION line)
?1.
Disconnect the following connector.
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
 
RDM switch 10P connector: disconnected
Test point 1
RDM switch 10P connector (female terminals) No. 10:
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. B5 (10 A) 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.
Disconnect the following connector.
Multipurpose camera unit 12P connector

?2.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
RDM switch 10P connector: disconnected
Multipurpose camera unit 12P connector: disconnected
Test point 1
Multipurpose camera unit 12P connector (female terminals) No. 7
Test point 2
RDM switch 10P connector (female terminals) No. 9:


Is there continuity?

     
YES
     
     
     
Go to step 6.
     
NO
     
     
     
Repair an open in the LDW OFF SW wire between the RDM switch and the multipurpose camera unit.?
6.
Open wire check (LDW OFF IND line):

Open wire check (LDW OFF IND line)
?1.
Check for continuity between test points 1 and 2.
Test condition
Vehicle OFF (LOCK) mode
RDM switch 10P connector: disconnected
Multipurpose camera unit 12P connector: disconnected
Test point 1
Multipurpose camera unit 12P connector (female terminals) No. 8
Test point 2
RDM switch 10P connector (female terminals) No. 2:


Is there continuity?

     
YES
     
     
     
     
NO
     
     
     
Repair an open in the LDW OFF IND wire between the RDM switch and the multipurpose camera unit.?