DTC C1426: Stop Light Switch OFF Stuck Malfunction [11/2016 - ]: Procedure

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

   Refer to ADJUSTMENT [12/2013 - ]

   OK

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

   HINT: 

   If the on/off status of the stop light switch assembly and the pressure increase information from the master cylinder pressure sensor do not match due to an improperly installed brake pedal or stop light switch assembly, this DTC may be stored. Therefore, be sure to check the installation condition of the pedal and stop light switch assembly before inspecting the input signals and other related parts.

Result:

NG 

ADJUST BRAKE PEDAL HEIGHT OR STOP LIGHT SWITCH ASSEMBLY INSTALLATION. 

Refer to ADJUSTMENT [12/2013 - ]

Result:

OK 

Go to next step 

1. Check that the stop lights come on when the brake pedal is depressed, and go off when the brake pedal is released.

   OK

   Condition	Illumination Condition
   Brake pedal depressed.	On
   Brake pedal released.	Off

Result:

NG 

See step  9

Result:

OK 

Go to next step 

1. Connect the Techstream to the DLC3.
2. Turn the ignition switch to ON.
3. Select the Data List using the Techstream.

   Refer to DATA LIST / ACTIVE TEST [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display	Measurement Item	Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch assembly	ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-
   Brake Pedal Load Sensing SW	Brake pedal load sensing switch	ON or OFF	ON: Brake pedal depressed beyond a specified point OFF: Brake pedal not depressed beyond a specified point	-

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display
   Stop Light SW
   Brake Pedal Load Sensing SW

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

   OK

   The Techstream displays ON or OFF according to brake pedal operation.

5. 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	Proceed to
   OK	A
   NG (The stop light switch assembly does not turn on.)	B
   NG (Turning on of the brake pedal load sensing switch is not confirmed.)	C
   NG (The brake pedal load sensing switch turns on first.)	D

Result:

B 

See step  5

Result:

C 

See step  7

Result:

D 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. 

Refer to REMOVAL [12/2013 - ]

Result:

A 

Go to next step 

1. Turn the ignition switch off.
2. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

3. Turn the ignition switch off.
4. Start the engine.
5. Depress the brake pedal several times to test the stop light circuit.
6. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   HINT: 

   If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

   Refer to PROBLEM SYMPTOMS TABLE [11/2016 - ]

Result:

A 

USE SIMULATION METHOD TO CHECK. 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2016 - ]

Result:

B 

REPLACE BRAKE ACTUATOR ASSEMBLY. 

Refer to REMOVAL [11/2016 - ]

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the A85 skid control ECU (brake actuator assembly) connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A85-35 (STP) - Body ground	Stop light switch assembly on (Brake pedal depressed)	8 to 14 V
   A85-35 (STP) - Body ground	Stop light switch assembly off (Brake pedal released)	Below 1.5 V

Result:

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) 

Result:

OK 

Go to next step 

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

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A85-25 (GND1) - Body ground	Always	Below 1 Ω

   HINT: 

   If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

   Refer to PROBLEM SYMPTOMS TABLE [11/2016 - ]

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

Result:

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. 

Refer to REMOVAL [11/2016 - ]

Result:

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT) 

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the A55 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.
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:

NG 

REPLACE BRAKE PEDAL SUPPORT ASSEMBLY. 

Refer to REMOVAL [12/2013 - ]

Result:

OK 

Go to next step 

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
2. Disconnect the A85 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
   A85-23 (FSW+) - A55-2 (FSW+)	Always	Below 1 Ω
   A85-23 (FSW+) or A55-2 (FSW+) - Body ground	Always	10 kΩ or higher
   A55-1 (FSW-) - Body ground	Always	Below 1 Ω

   HINT: 

   If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

   Refer to PROBLEM SYMPTOMS TABLE [11/2016 - ]

Result:

OK 

REPLACE BRAKE ACTUATOR ASSEMBLY. 

Refer to REMOVAL [11/2016 - ]

Result:

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

1. Check the stop light switch assembly.

   Refer to ON-VEHICLE INSPECTION [11/2016 - ]

   OK

   The stop light switch assembly is normal.

Result:

NG 

REPLACE STOP LIGHT SWITCH ASSEMBLY. 

Refer to REMOVAL [12/2013 - ]

Result:

OK 

Go to next step 

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

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Actuator Assembly))

2. Disconnect the A85 skid control ECU (brake actuator assembly) connector.
3. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A85-35 (STP) - Body ground	Stop light switch assembly on (Brake pedal depressed)	8 to 14 V
   A85-35 (STP) - Body ground	Stop light switch assembly off (Brake pedal released)	Below 1.5 V

Result:

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) 

Result:

OK 

Go to next step 

1. Turn the ignition switch off.
2. Reconnect the A85 skid control ECU (brake actuator assembly) connector.
3. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

4. Turn the ignition switch off.
5. Start the engine.
6. Depress the brake pedal several times to test the stop light circuit.
7. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [11/2016 - ]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   HINT: 

   • If the lighting system is normal but the DTC is still output, replace the skid control ECU (brake actuator assembly).

     Refer to REMOVAL [11/2016 - ]

   • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

     Refer to PROBLEM SYMPTOMS TABLE [11/2016 - ]

Result:

A 

USE SIMULATION METHOD TO CHECK. 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [11/2016 - ]

Result:

B 

INSPECT LIGHTING SYSTEM (STOP LIGHT CIRCUIT). 

Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2013 - ]