DTC Troubleshooting: C0023-14 - Honda FIT GK 2014-2020

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.	Select the BRAKE LIGHT RELAY TEST in the VSA FUNCTION TEST with the HDS

?5.

Check for DTCs with the HDS.

DTC Description	DTC
C0023-14 Brake Diag Circuit OFF Failure

Is DTC C0023-14 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. B6

Is the fuse OK?


	YES

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


	NO

Replace the fuse. If the fuse blows again, repair the short to body ground on the No. B6 fuse circuit.?

3.

Open wire check (BRK LAMP line) 1:

Open wire check (BRK LAMP line) 1

?1.

Disconnect the following connector.

VSA modulator-control unit 38P connector

?2.

Connect terminals 1 and 2 with a jumper wire.

Terminal 1	VSA modulator-control unit 38P connector No. 14
Terminal 2	Body ground

?3.	Turn the vehicle to the ON mode.

?4.	Check the brake lights without pressing the brake pedal.

Are the brake lights on?


	YES

Go to step 7.


	NO

Go to step 4.

4.

Open wire check (BRK LAMP line) 2:

Open wire check (BRK LAMP line) 2

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

?2.	Disconnect the jumper wire.

?3.	Remove the brake light relay.

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Brake light relay: disconnected
	VSA modulator-control unit 38P connector: disconnected
Test point 1	Brake light relay 5P socket (female terminals) No. 14:
Test point 2	VSA modulator-control unit 38P connector No. 14

Is there continuity?


	YES

The BRK LAMP wire is OK. Go to step 5.


	NO

Repair an open in the wire between the VSA modulator-control unit and the brake light relay.?

5.

Open wire check (IG1 VSA/ABS line):

Open wire check (IG1 VSA/ABS line)

?1.	Turn the vehicle to the ON mode.

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle ON mode
	Brake light relay: disconnected
	VSA modulator-control unit 38P connector: disconnected
Test point 1	Brake light relay 5P socket (female terminals) No. 12:
Test point 2	Body ground

Is there battery voltage?


	YES

The IG1 VSA/ABS wire is OK. Go to step 6.


	NO

Repair an open in the wire between the brake light relay and the No. C27 (7.5 A) fuse in the under-dash fuse/relay box.?

6.

Open wire check (+B STOP line):

Open wire check (+B STOP line)

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

?2.

Measure the voltage between test points 1 and 2.

Test condition	Vehicle OFF mode
	Brake light relay: disconnected
	VSA modulator-control unit 38P connector: disconnected
Test point 1	Brake light relay 5P socket (female terminals) No. 4:
Test point 2	Body ground

Is there battery voltage?


	YES

The +B STOP wire is OK. Go to step 7.


	NO

Repair an open in the wire between the brake light relay and the No. B6 (10 A) fuse in the under-hood fuse/relay box.?

7.

Open wire check (STOP LT line):

Open wire check (STOP LT line)

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

?2.	Disconnect the jumper wire (if equipped).

?3.	Remove the brake light relay (if connected).

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Brake light relay: disconnected
	VSA modulator-control unit 38P connector: disconnected
Test point 1	Brake light relay 5P socket (female terminals) No. 3:
Test point 2	VSA modulator-control unit 38P connector No. 34

Is there continuity?


	YES

The STOP LT wire is OK. Go to step 8.


	NO

Repair an open in the wire between the VSA modulator-control unit and the brake light relay.?

8.

Brake light relay check:

Brake light relay check

?1.	Substitute a known-good brake light relay.

?2.

Reconnect the following connector.

VSA modulator-control unit 38P connector

?3.	Turn the vehicle to the ON mode.

?4.	Clear the DTC with the HDS.

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

?6.	Select the BRAKE LIGHT RELAY TEST in the VSA FUNCTION TEST with the HDS

?7.

Check for DTCs with the HDS.

DTC Description	DTC
C0023-14 Brake Diag Circuit OFF Failure

Is DTC C0023-14 indicated?


	YES

Check for loose terminals and poor connections in the VSA modulator-control unit 38P connector. Check for any authorized service information related to the DTCs or symptoms you are troubleshooting. If they are OK, replace the VSA modulator-control unit.?


	NO

Replace the original brake light relay.?