DTC Troubleshooting: C0023-14 - Honda Accord CR/CT 2012-2017

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.	After the VSA indicator goes off, press the brake pedal for 3 seconds or more.

?5.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame
C0023-14 Brake Diag Circuit OFF Failure

Is DTC C0023-14 indicated?


	YES

The failure is duplicated. Go to step 2.


	NO

The failure is not duplicated. Go to step 5.

2.

Open wire check (STOP SW line):

Open wire check (STOP SW line)

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

?2.	Remove the brake light relay

?3.

Disconnect the following connectors.

Brake pedal position switch 4P connector

?4.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Brake pedal position switch 4P connector: disconnected
	Brake light relay: disconnected
Test point 1	Brake pedal position switch 4P connector No. 1
Test point 2	Brake light relay 5P socket No. 4

Is there continuity?


	YES

The STOP SW wire is OK. Go to step 3.


	NO

Repair an open in the wire between the brake pedal position switch and the brake light relay.?

3.

Open wire check (BRK DIAG line) 1:

Open wire check (BRK DIAG line) 1

?1.

Disconnect the following connector.

VSA modulator-control unit 38P connector

?2.

Check for continuity between test points 1 and 2.

Test condition	Vehicle OFF (LOCK) mode
	Brake pedal position switch 4P connector: disconnected
	Brake light relay: disconnected
	VSA modulator-control unit 38P connector: disconnected
Test point 1	Brake light relay 5P socket No. 1
Test point 2	VSA modulator-control unit 38P connector No. 34

Is there continuity?


	YES

The BRK DIAG wire is OK. Go to step 4.


	NO

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

4.

Brake light relay relay check (substitution):

Brake light relay relay check (substitution)

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

?2.

Reconnect the following connectors.

Brake pedal position switch 4P 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.	After the VSA indicator goes off, press the brake pedal for 3 seconds or more.

?7.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame
C0023-14 Brake Diag Circuit OFF Failure

Is DTC C0023-14 indicated?


	YES

Go to step 9.


	NO

Replace the original brake light relay.?

5.

Open wire check (BRK LAMP line) 1:

Open wire check (BRK LAMP line) 1

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

?2.

Disconnect the following connector.

VSA modulator-control unit 38P connector

?3.

Connect terminals 1 and 2 with a jumper wire.

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

?4.	Turn the vehicle to the ON mode.

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

Are the brake lights on?


	YES

Go to step 8.


	NO

Go to step 6.

6.

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 No. 5
Test point 2	VSA modulator-control unit 38P connector No. 14

Is there continuity?


	YES

The BRK LAMP wire is OK. Go to step 7.


	NO

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

7.

Open wire check (IG1 OPTION line):

Open wire check (IG1 OPTION 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 No. 3
Test point 2	Body ground

Is there battery voltage?


	YES

Replace the brake light relay.?


	NO

Repair an open in the wire between the brake light relay and the No. B7 (7.5 A) fuse in the under-dash fuse/relay box.?

8.

Open wire check (BRK DIAG line) 2:

Open wire check (BRK DIAG 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 No.1
Test point 2	VSA modulator-control unit 38P connector No. 34

Is there continuity?


	YES

The BRK DIAG wire is OK. Go to step 9.


	NO

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

9.

VSA modulator-control unit check (update):

VSA modulator-control unit check (update)

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

?2.	Install the brake light relay (if removed).

?3.

Reconnect the following connectors.

VSA modulator-control unit 38P connector (if disconnected)

?4.	Update the VSA modulator-control unit if it does not have the latest software.

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

?6.	After the VSA indicator goes off, press the brake pedal for 3 seconds or more.

?7.

Check for DTCs with the HDS.

DTC Description	DTC	Freeze Frame

Is DTC C0023-14 indicated?


	YES

Check for loose terminals in the VSA modulator-control unit 38P connector. If the VSA modulator-control unit was updated and the symptom/indication is still present, replace the VSA modulator-control unit.?


	NO

Troubleshooting is complete. If any other DTCs are indicated, go to the indicated DTCs troubleshooting.?