DTC C1425: Open in Stop Light Switch Circuit: Procedure

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

NG → See step   4 

OK: Go to next step 

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 .
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Stop Light SW	Stop light switch / ON or OFF	ON: Brake pedal depressed OFF: Brake pedal released	-

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

   OK

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

NG → See step   9 

OK: Go to next step 

1. Turn the ignition switch off.
2. Clear the DTCs. Refer to DTC CHECK / CLEAR .
3. Start the engine.
4. Depress the brake pedal several times to test the stop light circuit.
5. Check if the same DTC is recorded. Refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   DTC (C1425) is not output	A
   DTC (C1425) 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 .

B → See step   12 

A → See step   10 

1. Remove the STOP fuse from the main body ECU (instrument panel junction block).
   Fig 1: Identifying STOP Fuse

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   STOP (10 A) fuse	Always	Below 1 Ω

NG → REPLACE STOP FUSE 

OK: Go to next step 

1. Install the STOP fuse.
   Fig 2: Identifying Stop Light Switch Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Make sure that there is no looseness at the locking part and the connecting part of the connector.
3. Disconnect the stop light switch connector.
4. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   A1-2 - Body ground	Always	11 to 14 V

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 3: Inspecting Stop Light Switch

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Resistance

   Tester Connection	Switch Condition	Specified Condition
   1 - 2	Switch pin free	Below 1 Ω
   1 - 2	Switch pin pushed in	10 kΩ or higher

NG → See step   13 

OK: Go to next step 

1. Make sure that there is no looseness at the locking part and the connecting part of the connector.
   Fig 4: Identifying Skid Control ECU And Stop Light Switch Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the skid control ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A66-2 (STP) - A1-1	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the skid control ECU connector and the stop light switch connector.
2. Clear the DTCs. Refer to DTC CHECK / CLEAR .
3. Start the engine.
4. Depress the brake pedal several times to test the stop light circuit.
5. Check if the same DTC is recorded. Refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   DTC (C1425) is not output	A
   DTC (C1425) 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 .

B → See step   12 

A → See step   11 

1. Turn the ignition switch off.
   Fig 5: Identifying Skid Control ECU And Stop Light Switch Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Make sure that there is no looseness at the locking part and the connecting part of the connectors.
3. Disconnect the skid control ECU connector and the stop light switch connector.
4. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   A66-2 (STP) - A1-1	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. Refer to PROBLEM SYMPTOMS TABLE .

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK → See step   12