DTC C0040-9E: Brake Pedal Switch "A" Stuck On; DTC C0040-9F: Brake Pedal Switch "A" Stuck Off [11/2023 - ]: Procedure

1. Check the Data List using the GTS.

   Chassis > Brake/EPB > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch assembly (STP terminal input)	OFF / ON	OFF: Brake pedal released ON: Brake pedal depressed	HINT:  The brake pedal state is determined using the voltage at terminal STP
   Brake Pedal Load Sensing SW	Brake pedal load sensing switch (brake pedal support assembly)	OFF / ON	OFF: Brake pedal load sensing switch (brake pedal support assembly) OFF ON: Brake pedal load sensing switch (brake pedal support assembly) ON	-

2. 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 ON or OFF according to brake pedal operation.

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

   OK

   First the stop light switch turns on, and then the brake pedal load sensing switch (brake pedal support assembly) turns 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
   C0040-9E and C0040-9F are not output	A
   C0040-9E and C0040-9F are output	B

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2021 - ] 

Result: 

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. Refer to  REMOVAL [11/2022 - ] 

1. Turn the ignition switch off.
2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the A167 brake pedal load sensing switch (brake pedal support assembly) connector.
   NOTE:

   • Do not remove the brake pedal load sensing switch from the brake pedal support assembly.
   • When there is a malfunction in the brake pedal load sensing switch, replace the brake pedal support assembly.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Component without harness connected (Brake Pedal Load Sensing Switch (Brake Pedal Support Assembly))

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   2 (FSW+) - 1 (FSW-)	Brake pedal load sensing switch off (Brake pedal depressed)	950 to 1050 Ω
   2 (FSW+) - 1 (FSW-)	Brake pedal load sensing switch on (Brake pedal released)	203 to 223 Ω

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. Refer to  REMOVAL [11/2022 - ] 

Result: 

OK 

See step  5

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
2. Disconnect the A151 skid control ECU (brake actuator assembly) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A151-10 (FSW+) - A167-2 (FSW+)	Always	Below 1 Ω
   A151-10 (FSW+) - Body ground	Always	10 kΩ or higher
   A167-2 (FSW+) - Body ground	Always	10 kΩ or higher
   A167-1 (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 [11/2022 - ] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Turn the ignition switch off.
2. Check the brake pedal height.

   Refer to ADJUSTMENT [11/2022 - ]

3. Check the stop light switch assembly installation.

   Refer to INSTALLATION [09/2021 - ]

   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 [11/2022 - ] 

Result: 

NG 

ADJUST BRAKE PEDAL OR STOP LIGHT SWITCH ASSEMBLY. Refer to  ADJUSTMENT [11/2022 - ]