DTC Troubleshooting: B12C6 (5-door) - Honda Civic FC/FK 2016-2021

1.

Problem verification:

Problem verification

?1.	Clear the DTCs with the HDS.

?2.	Press the engine start/stop switch at least 10 times.

?3.

Check for DTCs with the HDS.

DTC Description	DTC
B12C6 Electric Steering Lock Switch C/D Monitor Circuit Failure

Is DTC B12C6 indicated?


	YES

Go to step 2.


	NO

Intermittent failure, the system is OK at this time. Check for loose or poor connections.?

2.

ESL SW line check 1:

ESL SW line check 1

?1.

Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
Electrical Steering Lock SWITCH C	OFF
Electrical Steering Lock SWITCH D	OFF

Are ELECTRICAL STEERING LOCK SWITCH C and ELECTRICAL STEERING LOCK SWITCH D data list values OFF?


	YES

Go to step 8.


	NO

Go to step 3.

3.

ESL SW line check 2:

ESL SW line check 2

?1.

Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
Electrical Steering Lock SWITCH C	OFF
Electrical Steering Lock SWITCH D	OFF

Are ELECTRICAL STEERING LOCK SWITCH C data list value OFF?


	YES

Go to step 9.


	NO

Go to step 4.

4.

ESL SW line check 3:

ESL SW line check 3

?1.

Check the parameter(s) below with the HDS.

Signal	Threshold		Current conditions
Signal	Values	Unit	Values	Unit
Electrical Steering Lock SWITCH C	OFF
Electrical Steering Lock SWITCH D	OFF

Are ELECTRICAL STEERING LOCK SWITCH D data list value OFF?


	YES

Go to step 11.


	NO

Go to step 5.

5.

Shorted wire check (ESL SW C line) 1:

Shorted wire check (ESL SW C line) 1

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

?2.

Disconnect the following connector.

Electric steering lock 12P connector

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector No. 9
Test point 2	Body ground

Is there continuity?


	YES

Go to step 13.


	NO

Go to step 6.

6.

Shorted wire check (ESL SW D line) 1:

Shorted wire check (ESL SW D line) 1

?1.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector No. 10
Test point 2	Body ground

Is there continuity?


	YES

Go to step 7


	NO

The ESL SW D wire is OK. Replace the steering lock.?

7.

Shorted wire check (ESL SW D line) 2:

Shorted wire check (ESL SW D line) 2

?1.

Disconnect the following connector.

Body control module connector G (32P)

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Body control module connector G (32P): disconnected
Test point 1	Electric steering lock 12P connector No. 10
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to ground in the wire.?


	NO

The ESL SW D wire is OK. Replace the body control module.?

8.

Open wire check (GND line):

Open wire check (GND line)

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

?2.

Disconnect the following connector.

Electric steering lock 12P connector

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector No. 7
Test point 2	Body ground

Is there continuity?


	YES

The GND wire is OK. Replace the steering lock.?


	NO

Repair an open or high resistance in the ground wire or poor ground (G505).?

9.

Open wire check (ESL SW C line) 1:

Open wire check (ESL SW C line) 1

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

?2.

Disconnect the following connector.

Electric steering lock 12P connector

?3.	Turn the vehicle to the ON mode.

?4.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector No. 9
Test point 2	Body ground

Is there battery voltage?


	YES

The ESL SW C wire is OK. Replace the steering lock.?


	NO

Go to step 10.

10.

Open wire check (ESL SW C line) 2:

Open wire check (ESL SW C line) 2

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

?2.

Disconnect the following connector.

Body control module connector G (32P)

?3.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Body control module connector G (32P): disconnected
Test point 1	Electric steering lock 12P connector No. 9
Test point 2	Body control module connector G (32P) No. 4

Is there continuity?


	YES

The ESL SW C wire is OK. Replace the body control module.?


	NO

Repair an open or high resistance in the wire.?

11.

Open wire check (ESL SW D line) 1:

Open wire check (ESL SW D line) 1

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

?2.

Disconnect the following connector.

Electric steering lock 12P connector

?3.	Turn the vehicle to the ON mode.

?4.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode Electric steering lock 12P connector: disconnected
Test point 1	Electric steering lock 12P connector No. 10
Test point 2	Body ground

Is there battery voltage?


	YES

The ESL SW D wire is OK. Replace the steering lock.?


	NO

Go to step 12.

12.

Open wire check (ESL SW D line) 2:

Open wire check (ESL SW D line) 2

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

?2.

Disconnect the following connector.

Body control module connector G (32P)

?3.

Check for continuity between test points 1 and 2 respectively.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Body control module connector G (32P): disconnected
Test point 1	Electric steering lock 12P connector No. 10
Test point 2	Body control module connector G (32P) No. 5

Is there continuity?


	YES

The ESL SW D wire is OK. Replace the body control module.?


	NO

Repair an open or high resistance in the wire.?

13.

Shorted wire check (ESL SW C line) 2:

Shorted wire check (ESL SW C line) 2

?1.

Disconnect the following connector.

Body control module connector G (32P)

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode Electric steering lock 12P connector: disconnected Body control module connector G (32P): disconnected
Test point 1	Electric steering lock 12P connector No. 9
Test point 2	Body ground

Is there continuity?


	YES

Repair a short to ground in the wire.?


	NO

The ESL SW C wire is OK. Replace the body control module.?