DTC C0040-9E: Brake Pedal Switch "A" Stuck On; DTC C0040-9F: Brake Pedal Switch "A" Stuck Off [10/2022 - ]: Procedure

1. Check if the same DTC is output.

   Chassis > Brake/EPB > Trouble Codes 

   HINT: 

   When P0571-11 and/or P0571-13 is output together with C0040-9E and/or C0040-9F, inspect and repair the trouble areas indicated by P0571-11 and/or P0571-13 first.

   Result

   Result	Proceed to
   C0040-9E and P0571-11 are output	A
   C0040-9E and P0571-13 are output	B
   C0040-9F and P0571-11 are output	C
   C0040-9F and P0571-13 are output	D
   Only C0040-9E or C0040-9F is output	E

Result: 

A 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

Result: 

B 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

Result: 

C 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

Result: 

D 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS 

Result: 

E 

See step  2

Pre-procedure1

• Connect the GTS to the DLC3.
• Turn the ignition switch to ON.

• Select the Data List using the GTS.

  HINT: 

  Refer to DATA LIST / ACTIVE TEST [10/2022 - ]

  Chassis > Brake/EPB > Data List 

  Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
  Stop Light SW	Stop light switch assembly status (STP or STP2 terminal input)	OFF / ON	OFF: Brake pedal released ON: Brake pedal depressed	HINT:  Stop light control relay off: STP terminal status displayed. Stop light control relay on: STP2 terminal status displayed.
  Brake Pedal Load Sensing SW	Brake pedal load sensing switch	OFF / ON	OFF: Brake pedal released ON: Brake pedal depressed	-

  Chassis > Brake/EPB > Data List 

  Tester Display
  Stop Light SW
  Brake Pedal Load Sensing SW

• Check that the stop light switch display and brake pedal load sensing switch display observed on the GTS change according to brake pedal operation.

  OK

  The GTS displays OFF / ON according to brake pedal operation.

• Slowly depress the brake pedal, and check when the stop light switch assembly and brake pedal load sensing switch turn on.

  OK

  First the stop light switch assembly should turn on, and then the brake pedal load sensing switch should turn on.

  Result

  Result	Proceed to
  OK	A
  NG (Turning on of the brake pedal load sensing switch is not confirmed.)	B
  NG (The brake pedal load sensing switch turns on first.)	C

Post-procedure1

• None

Result: 

B 

See step  5

Result: 

C 

See step  7

Result: 

A 

See step  3

Pre-procedure1

• None

• Operate the GTS to clear the codes. Enter the following menus: Chassis / Brake/EPB / Trouble Codes.

  Chassis > Brake/EPB > Clear DTCs 

  Result

  Proceed to
  NEXT

Post-procedure1

• Press the DTC clear button.
• Turn the ignition switch off.

Result: 

NEXT 

See step  4

Pre-procedure1

• Start the engine.
• Perform a road test.

• Read the DTCs following the prompts on the GTS. Enter the following menus: Chassis / Brake/EPB / Trouble Codes.

  Chassis > Brake/EPB > Trouble Codes 

• Check if the same DTC is output.

  Result

  Result	Proceed to
  C0040-9E and C0040-9F are not output	A
  C0040-9E or C0040-9F is output	B

Post-procedure1

• None

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - ] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Pre-procedure1

• Turn the ignition switch off.

• Inspect the brake pedal load sensing switch (brake pedal support assembly).

  Refer to ON-VEHICLE INSPECTION [10/2022 - ] 

  OK

  The brake pedal load sensing switch (brake pedal support assembly) is normal.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

NG 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

OK 

See step  6

• Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  OK

  The connector is securely connected.

Pre-procedure1

• Disconnect the A35 brake pedal load sensing switch (brake pedal support assembly) connector.
• Disconnect the A31 skid control ECU (brake actuator assembly) connector.

• Measure the resistance according to the value(s) in the table below.

  Standard Resistance

  Tester Connection	Condition	Specified Condition	Result
  A35-2 (FSW+) - A31-28 (FSW+)	Always	Below 1 Ω	Ω
  A35-2 (FSW+) or A31-28 (FSW+) - Body ground	Always	10 kΩ or higher	kΩ
  A35-1 (FSW-) - Body ground	1 minute or more after disconnecting the cable from the negative (-) battery terminal	Below 1 Ω	Ω

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Pre-procedure1

• Turn the ignition switch off.

• Check the brake pedal height and stop light switch assembly installation.

  HINT: 

  Refer to ADJUSTMENT [10/2022 - ]

  OK

  The brake pedal height and stop light switch assembly installation are normal.

  Result

  Proceed to
  OK
  NG

Post-procedure1

• None

Result: 

OK 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. Refer to  REMOVAL [10/2022 - ] 

Result: 

NG 

ADJUST BRAKE PEDAL HEIGHT OR STOP LIGHT SWITCH ASSEMBLY INSTALLATION. Refer to  ADJUSTMENT [10/2022 - ]