DTC 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 (IDAS)

*1: Without auto idle stop system*2: With auto idle stop system

1. 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

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

   -2. Check the following fuse.

   Fuse	No. D5 (10 A) *1 No. F7 (7.5 A) *2
   Location	Under-dash fuse/relay box *1 Auxiliary under-dash fuse/relay box *2

   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. D5 (10 A) *1/F7 (7.5 A) *2 fuse circuit.

3. Open wire check (IG1 OPTION *1/IG1 EBB *2 line):-1.

   Disconnect the following connector.

   CMBS OFF/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/RDM switch 10P connector: disconnected
   Test point 1	CMBS OFF/RDM switch 10P connector (female terminals) No. 5:
   Test point 2	Body ground

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

   Is there battery voltage?

   YES 

   IG1 OPTION *1/IG1 EBB *2 wire is OK. Go to step 4.

   NO 

   Repair an open in the IG1 OPTION *1/IG1 EBB *2 wire between the RDM switch and No. D5 (10 A) *1/F7 (7.5 A) *2 fuse in the under-dash fuse/relay box *1/auxiliary under-dash fuse/relay box *2.

4. 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 

   Replace the RDM switch .

5. 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
   	CMBS OFF/RDM switch 10P connector: disconnected
   	Multipurpose camera unit 12P connector: disconnected
   Test point 1	Multipurpose camera unit 12P connector No. 7
   Test point 2	CMBS OFF/RDM switch 10P connector (female terminals) No. 4:

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

   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)

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

   Test condition	Vehicle OFF (LOCK) mode
   	CMBS OFF/RDM switch 10P connector: disconnected
   	Multipurpose camera unit 12P connector: disconnected
   Test point 1	Multipurpose camera unit 12P connector No. 8
   Test point 2	CMBS OFF/RDM switch 10P connector (female terminals) No. 2:

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

   Is there continuity?

   YES 

   Replace the multipurpose camera unit .

   NO 

   Repair an open in the LDW OFF IND wire between the RDM switch and the multipurpose camera unit.