DTC C0023:62/C0040:64 [DSC HU/CM]

id040262906400

DTC

C0023:62

Brake switch

C0040:64

DETECTION CONDITION

•  C0023:62

―  Brake light ON signal is not input even though the brake light request signal is input

―  Brake light ON signal is input even though the brake light request signal is not input

―  Brake light request signal is not input even though the brake fluid pressure sensor signal reaches the specified value

―  Brake light request signal is input even though the brake fluid pressure sensor signal does not reach the specified value

―  Communication error with brake light is detected in CAN communication via Body Control Module (BCM)

•  C0040:64

―  Brake switch ON signal is input for 6 min or more when driving at a vehicle speed of 20 km/h {12 mph} or more

―  A brake switch ON signal is not input when the brake fluid pressure sensor signal reaches the specified value

FAIL-SAFE FUNCTION

Refer to DTC TABLE. (See DTC TABLE [DSC HU/CM].)

POSSIBLE CAUSE

•  Open or short to GND circuit in wiring harness between IG1 relay and DSC HU/CM terminal Q

•  Open or short to power supply circuit in wiring harness between brake switch terminal D and PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5)

•  Open or short to power supply circuit in wiring harness between brake switch terminal D and PCM terminal 2AA (SKYACTIV-D 1.5)

•  Brake switch malfunction

•  Body Control Module (BCM) malfunction (brake light circuit)

•  PCM malfunction

•  Poor connection at each connector

Diagnostic Procedure

Step

Inspection

Action

1

INSPECT POWER SUPPLY CIRCUIT IN DSC HU/CM

•  Switch the ignition OFF.

•  Disconnect the DSC HU/CM connector.

•  Measure the voltage between DSC HU/CM terminal Q (wiring harness-side) and body ground.

•  Is the voltage within followings?

―  Ignition switch OFF: 1 V or less

―  Ignition switch ON (engine off): B+

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector between IG1 relay and DSC HU/CM terminal Q.

If there is a common connector:

•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open or short circuit.

•  Repair or replace the malfunctioning part.

If there is no common connector:

•  Repair or replace the wiring harness which has an open or short circuit.

Go to Step8.

2

INSPECT BRAKE SWITCH SIGNALCIRCUIT

•  Measure the voltage as followings:

―  PCM terminal 2G (wiring harness-side)—body ground (SKYACTIV-G 1.3, SKYACTIV-G 1.5)

―  PCM terminal 2AA (wiring harness-side)—body ground (SKYACTIV-D 1.5)

•  Is the voltage within followings?

―  Brake pedal depressed: B+

―  Brake pedal released: 1 V or less

Yes

Go to Step8.

No

•  If it is B+ under any condition, then go to the next step.

•  If it is 1 V or less under any condition, then go to Step 4

3

INSPECT BRAKE SWITCH SIGNALCIRCUIT FOR SHORT TO POWER SUPPLY

•  Disconnect the brake switch connector.

•  Measure the voltage between brake switch terminal D (wiring harness-side) and body ground.

•  Is the voltage 1 V or less?

Yes

Go to Step5.

No

Refer to the wiring diagram and verify whether or not there is a common connector in the followings:

•  Brake switch terminal D—PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5)

•  Brake switch terminal D—PCM terminal 2AA (SKYACTIV-D 1.5)

If there is a common connector:

•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply.

•  Repair or replace the malfunctioning part.

If there is no common connector:

•  Repair or replace the wiring harness which has a short to power supply.

Go to Step8.

4

INSPECT BRAKE SWITCH SIGNALCIRCUIT FOR OPEN CIRCUIT

•  Disconnect the PCM connector.

•  Inspect for continuity as followings:

―  Brake switch terminal D (wiring harness-side)—PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5)

―  Brake switch terminal D (wiring harness-side)—PCM terminal 2AA (SKYACTIV-G 1.5)

•  Is there continuity?

Yes

Go to the next step.

No

Refer to the wiring diagram and verify whether or not there is a common connector in the followings:

•  Brake switch terminal D—PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5)

•  Brake switch terminal D—PCM terminal 2AA (SKYACTIV-D 1.5)

If there is a common connector:

•  Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.

•  Repair or replace the malfunctioning part.

If there is no common connector:

•  Repair or replace the wiring harness which has an open circuit.

Go to Step8.

5

INSPECT BRAKE SWITCH

•  Inspect brake switch.
(See BRAKE SWITCH INSPECTION.)

•  Is the brake switch normal?

Yes

Go to the next step.

No

Replace the brake switch, then go to Step8.

(See BRAKE PEDAL REMOVAL/INSTALLATION [L.H.D.].)

(See BRAKE PEDAL REMOVAL/INSTALLATION [R.H.D.].)

6

VERIFY BODY CONTROL MODULE (BCM) DTC

•  Using the M-MDS, perform the Body Control Module (BCM) DTC inspection.
(See DTC INSPECTION [BCM].)

•  Are any DTCs present?

Yes

Go to applicable DTC inspection.

(See DTC TABLE [BCM].)

DTC troubleshooting completed, then go to Step8.

No

Go to the next step.

7

VERIFY PCM DTC

•  Using the M-MDS, perform the PCM DTC inspection.
(See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 1.3, SKYACTIV-G 1.5].)

(See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 1.5].)

•  Are any DTCs present?

Yes

Go to applicable DTC inspection.

(See DTC TABLE [SKYACTIV-G 1.3, SKYACTIV-G 1.5].)

(See DTC TABLE [SKYACTIV-D 1.5].)

DTC troubleshooting completed, then go to the next step.

No

Go to the next step.

8

VERIFY DTC TROUBLESHOOTING COMPLETED

•  Reconnect all disconnected connectors.

•  Using the M-MDS, clear the DTC from the DSC HU/CM.
(See CLEARING DTC [DSC HU/CM].)

•  Start the engine and drive the vehicle at 10 km/h {6.2 mph} or more.

•  Using the M-MDS, perform the DSC HU/CM DTC inspection.
(See DTC INSPECTION [DSC HU/CM].)

•  Is the same DTC present?

Yes

Repeat the inspection from Step1.

If the malfunction recurs, replace the DSC HU/CM, then go to the next step.

(See DSC HU/CM REMOVAL/INSTALLATION [L.H.D.].)

(See DSC HU/CM REMOVAL/INSTALLATION [R.H.D.].)

No

Go to the next step.

9

VERIFY NO DTC IS PRESENT

•  Are any DTCs present?

Yes

Go to applicable DTC inspection.

(See DTC TABLE [DSC HU/CM].)

No

DTC troubleshooting completed.

DTC	C0023:62	Brake switch
	C0040:64
DETECTION CONDITION		• C0023:62 ― Brake light ON signal is not input even though the brake light request signal is input ― Brake light ON signal is input even though the brake light request signal is not input ― Brake light request signal is not input even though the brake fluid pressure sensor signal reaches the specified value ― Brake light request signal is input even though the brake fluid pressure sensor signal does not reach the specified value ― Communication error with brake light is detected in CAN communication via Body Control Module (BCM) • C0040:64 ― Brake switch ON signal is input for 6 min or more when driving at a vehicle speed of 20 km/h {12 mph} or more ― A brake switch ON signal is not input when the brake fluid pressure sensor signal reaches the specified value
FAIL-SAFE FUNCTION		Refer to DTC TABLE. (See DTC TABLE [DSC HU/CM].)
POSSIBLE CAUSE		• Open or short to GND circuit in wiring harness between IG1 relay and DSC HU/CM terminal Q • Open or short to power supply circuit in wiring harness between brake switch terminal D and PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5) • Open or short to power supply circuit in wiring harness between brake switch terminal D and PCM terminal 2AA (SKYACTIV-D 1.5) • Brake switch malfunction • Body Control Module (BCM) malfunction (brake light circuit) • PCM malfunction • Poor connection at each connector

Step	Inspection		Action
1	INSPECT POWER SUPPLY CIRCUIT IN DSC HU/CM • Switch the ignition OFF. • Disconnect the DSC HU/CM connector. • Measure the voltage between DSC HU/CM terminal Q (wiring harness-side) and body ground. • Is the voltage within followings? ― Ignition switch OFF: 1 V or less ― Ignition switch ON (engine off): B+	Yes	Go to the next step.
1		No	Refer to the wiring diagram and verify whether or not there is a common connector between IG1 relay and DSC HU/CM terminal Q. If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open or short circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open or short circuit. Go to Step8.
2	INSPECT BRAKE SWITCH SIGNALCIRCUIT • Measure the voltage as followings: ― PCM terminal 2G (wiring harness-side)—body ground (SKYACTIV-G 1.3, SKYACTIV-G 1.5) ― PCM terminal 2AA (wiring harness-side)—body ground (SKYACTIV-D 1.5) • Is the voltage within followings? ― Brake pedal depressed: B+ ― Brake pedal released: 1 V or less	Yes	Go to Step8.
2		No	• If it is B+ under any condition, then go to the next step. • If it is 1 V or less under any condition, then go to Step 4
3	INSPECT BRAKE SWITCH SIGNALCIRCUIT FOR SHORT TO POWER SUPPLY • Disconnect the brake switch connector. • Measure the voltage between brake switch terminal D (wiring harness-side) and body ground. • Is the voltage 1 V or less?	Yes	Go to Step5.
3		No	Refer to the wiring diagram and verify whether or not there is a common connector in the followings: • Brake switch terminal D—PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5) • Brake switch terminal D—PCM terminal 2AA (SKYACTIV-D 1.5) If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to power supply. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has a short to power supply. Go to Step8.
4	INSPECT BRAKE SWITCH SIGNALCIRCUIT FOR OPEN CIRCUIT • Disconnect the PCM connector. • Inspect for continuity as followings: ― Brake switch terminal D (wiring harness-side)—PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5) ― Brake switch terminal D (wiring harness-side)—PCM terminal 2AA (SKYACTIV-G 1.5) • Is there continuity?	Yes	Go to the next step.
4		No	Refer to the wiring diagram and verify whether or not there is a common connector in the followings: • Brake switch terminal D—PCM terminal 2G (SKYACTIV-G 1.3, SKYACTIV-G 1.5) • Brake switch terminal D—PCM terminal 2AA (SKYACTIV-D 1.5) If there is a common connector: • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit. • Repair or replace the malfunctioning part. If there is no common connector: • Repair or replace the wiring harness which has an open circuit. Go to Step8.
5	INSPECT BRAKE SWITCH • Inspect brake switch. (See BRAKE SWITCH INSPECTION.) • Is the brake switch normal?	Yes	Go to the next step.
5		No	Replace the brake switch, then go to Step8. (See BRAKE PEDAL REMOVAL/INSTALLATION [L.H.D.].) (See BRAKE PEDAL REMOVAL/INSTALLATION [R.H.D.].)
6	VERIFY BODY CONTROL MODULE (BCM) DTC • Using the M-MDS, perform the Body Control Module (BCM) DTC inspection. (See DTC INSPECTION [BCM].) • Are any DTCs present?	Yes	Go to applicable DTC inspection. (See DTC TABLE [BCM].) DTC troubleshooting completed, then go to Step8.
6		No	Go to the next step.
7	VERIFY PCM DTC • Using the M-MDS, perform the PCM DTC inspection. (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-G 1.3, SKYACTIV-G 1.5].) (See ON-BOARD DIAGNOSTIC TEST [SKYACTIV-D 1.5].) • Are any DTCs present?	Yes	Go to applicable DTC inspection. (See DTC TABLE [SKYACTIV-G 1.3, SKYACTIV-G 1.5].) (See DTC TABLE [SKYACTIV-D 1.5].) DTC troubleshooting completed, then go to the next step.
7		No	Go to the next step.
8	VERIFY DTC TROUBLESHOOTING COMPLETED • Reconnect all disconnected connectors. • Using the M-MDS, clear the DTC from the DSC HU/CM. (See CLEARING DTC [DSC HU/CM].) • Start the engine and drive the vehicle at 10 km/h {6.2 mph} or more. • Using the M-MDS, perform the DSC HU/CM DTC inspection. (See DTC INSPECTION [DSC HU/CM].) • Is the same DTC present?	Yes	Repeat the inspection from Step1. If the malfunction recurs, replace the DSC HU/CM, then go to the next step. (See DSC HU/CM REMOVAL/INSTALLATION [L.H.D.].) (See DSC HU/CM REMOVAL/INSTALLATION [R.H.D.].)
8		No	Go to the next step.
9	VERIFY NO DTC IS PRESENT • Are any DTCs present?	Yes	Go to applicable DTC inspection. (See DTC TABLE [DSC HU/CM].)
9	VERIFY NO DTC IS PRESENT • Are any DTCs present?	No	DTC troubleshooting completed.