DTC C0040-9E: Brake Pedal Switch "A" Stuck On; DTC C0040-9F: Brake Pedal Switch "A" Stuck Off [12/2019 - ]: Procedure

1. Check that the stop light switch display and brake pedal load sensing switch (brake pedal support assembly) display observed on the GTS change according to brake pedal operation.

   Chassis > Brake/EPB > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch assembly (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 (brake pedal support assembly)	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

   OK

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

2. Slowly depress the brake pedal, and check when the stop light switch assembly and brake pedal load sensing switch (brake pedal support assembly) turn on.

   OK

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

   Result

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

Result: 

B 

See step  4

Result: 

C 

See step  6

Result: 

A 

See step  2

1. Clear the DTCs.

   Chassis > Brake/EPB > Clear DTCs 

2. Turn the ignition switch off.

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  3

1. Based on the Freeze Frame Data and interview with the customer, attempt to reproduce the conditions when the malfunction occurred.
2. Check if the same DTC is output.

   Chassis > Brake/EPB > Trouble Codes 

   Result

   Result	Proceed to
   DTC C0040-9E and C0040-9F are not output.	A
   DTC C0040-9E and/or C0040-9F are output.	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023]  , or refer to  REMOVAL [11/2023 - ] 

1. Turn the ignition switch off.
2. Inspect the brake pedal load sensing switch (brake pedal support assembly).

   Refer to ON-VEHICLE INSPECTION [12/2019 - ]

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023]  , or refer to  REMOVAL [11/2023 - ] 

Result: 

OK 

See step  5

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

   OK

   The connector is securely connected.

2. Disconnect the A39 skid control ECU (brake actuator assembly) connector.
3. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A45-2 (FSW+) - A39-28 (FSW+)	Always	Below 1 Ω
   A45-2 (FSW+) or A39-28 (FSW+) - Body ground	Always	10 kΩ or higher
   A45-1 (FSW-) - Body ground	1 minute or more after disconnecting the cable from the negative (-) auxiliary battery terminal	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023]  , or refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Turn the ignition switch off.
2. Check the brake pedal height and stop light switch assembly installation.

   Refer to ADJUSTMENT [12/2019 - 10/2022] , or refer to ADJUSTMENT [10/2022 - ]

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. Refer to  REMOVAL [12/2019 - 10/2022]  , or refer to  REMOVAL [10/2022 - 11/2023]  , or refer to  REMOVAL [11/2023 - ] 

Result: 

NG 

ADJUST BRAKE PEDAL HEIGHT OR STOP LIGHT SWITCH ASSEMBLY INSTALLATION. Refer to  ADJUSTMENT [12/2019 - 10/2022]  , or refer to  ADJUSTMENT [10/2022 - ]