DTC B2A70-12

WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2020 Acura RLX, 2019 Acura RLX, 2018 Acura RLX, 2017 Acura RLX, and 2016 Acura RLX. However, it is still accessible from the selected car via links, so may be relevant.

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

DTC (IDAS)

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 press the RDM OFF switch.

-5. Check for DTCs with the HDS.

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 .

Fuse check

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

-2. Check the following fuse.

Fuse	No. D24 (7.5 A)
Location	Driver's under-dash fuse/relay box

Is the fuse OK?

YES

The fuse is OK. Reinstall the fuse, then go to step 3.

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. D24 (7.5 A) fuse circuit.

Open wire check (IG1 DR2 line)

-1. Disconnect the following connector.

Multi visor switch 16P connector

-2. Turn the vehicle to the ON mode.

-3. Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Multi visor switch 16P connector: disconnected
Test point 1	Multi visor switch 16P connector No. 8
Test point 2	Body ground

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

Is there battery voltage?

YES

The IG1 DR2 wire is OK. Go to step 4.

Repair an open in the wire between the multi visor switch and No. D24 (7.5 A) fuse in the driver's under-dash fuse/relay box.

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

-2. Test the RDM OFF switch .

Is the RDM OFF switch OK?

YES

RDM OFF switch is OK. Go to step 5.

NO

Replace the multi visor switch .

Open wire check (LDW OFF SW line)

-1. Disconnect the following connector.

Multipurpose camera unit 20P connector

-2. Turn the vehicle to the ON mode.

-3. Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF mode
	Multipurpose camera unit 20P connector: disconnected
Test point 1	Multipurpose camera unit 20P connector No. 8
Test point 2	Multi visor switch 16P connector No. 16

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

Is there continuity?

YES

The LDW SW wire is OK. Go to step 6.

Repair an open in the wire between the multi visor switch and the multipurpose camera unit.

Multipurpose camera unit check (update)
-1. Reconnect the following connectors.

Multipurpose camera unit 20P connector

Multi visor switch 16P connector

-2. Update the multipurpose camera unit if it does not have the latest software .

-3. Turn the vehicle to the OFF (LOCK) mode.

-4. Turn the vehicle to the ON mode, then press the RDM OFF switch.

-5. Check for DTCs with the HDS.

Is DTC B2A70-12 indicated?

YES

Check for loose terminals in the multipurpose camera unit 20P connector. If the multipurpose camera unit was updated and the symptom/indication is still present, replace the multipurpose camera unit .

NO

Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTC's troubleshooting.