DTC C1249: Open Circuit in Stop Light Switch Circuit [02/2019 - 12/2021]: Procedure

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

   Refer to DATA LIST / ACTIVE TEST [02/2019 - 12/2021]

   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	-

   Chassis > ABS/VSC/TRAC > Data List 

   Tester Display
   Stop Light SW

4. Check that the stop light switch assembly display observed on the Techstream changes according to brake pedal operation.

   OK

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

   Result

   Proceed to
   OK
   NG

Result: 

NG 

See step  3

Result: 

OK 

See step  2

1. Clear the DTCs.

   Refer to DTC CHECK / CLEAR [02/2019 - 12/2021]

   Chassis > ABS/VSC/TRAC > Clear DTCs 

2. Turn the ignition switch off.
3. Turn the ignition switch to ON (READY).
4. Depress the brake pedal several times to test the stop light circuit.
5. Check if the same DTC is output.

   Refer to DTC CHECK / CLEAR [02/2019 - 12/2021]

   Chassis > ABS/VSC/TRAC > Trouble Codes 

   Result

   Result	Proceed to
   DTC C1249 is not output.	A
   DTC C1249 is output.	B

   HINT: 

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

   Refer to PROBLEM SYMPTOMS TABLE [11/2018 - 12/2021]

Result: 

A 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [11/2018 - ] 

Result: 

B 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [02/2019 - 10/2019]  , or refer to  REMOVAL [10/2019 - 08/2020]  , or refer to  REMOVAL [08/2020 - 12/2021] 

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the A42 skid control ECU (brake booster with master cylinder assembly) connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A42-33 (STP) - Body ground	Stop light switch assembly on (Brake pedal depressed)	11 to 14 V
   A42-33 (STP) - Body ground	Stop light switch assembly off (Brake pedal released)	Below 1.5 V

   HINT: 

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

   Refer to PROBLEM SYMPTOMS TABLE [11/2018 - 12/2021]

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY. Refer to  REMOVAL [02/2019 - 10/2019]  , or refer to  REMOVAL [10/2019 - 08/2020]  , or refer to  REMOVAL [08/2020 - 12/2021] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT)