Inspection Procedure

1. Check that the stop light comes on when the brake pedal is depressed, and goes off when the brake pedal is released.

   OK: Stop light switch function is normal. 

   HINT:

   Check the stop light bulb as it may have burnt out.

NG:  Go to step  4

OK: Go To Next Step 

1. Disconnect the skid control ECU connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage 

   TESTER CONNECTION AND SPECIFIED CONDITION TABLE
   
   

   Tester Connection	Condition	Specified Condition
   S28-7 (STP) - Body ground	Stop light switch ON (Brake pedal depressed)	8 to 14 V
   S28-7 (STP) - Body ground	Stop light switch OFF (Brake pedal released)	Below 1.5 V

   Fig 1: Identifying S28 Skid Control ECU (STP Terminal)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Result 

   RESULT REFERENCE TABLE
   
   

   Result	Proceed to
   OK	A
   NG	B

B: REPAIR OR REPLACE HARNESS OR CONNECTOR (STP CIRCUIT) 

A: Go To Next Step 

B: CHECK FOR INTERMITTENT PROBLEMS (See  CHECK FOR INTERMITTENT PROBLEMS   ) 

A: REPLACE MASTER CYLINDER SOLENOID 

1. Disconnect the stop light switch connector.
2. Measure the voltage according to the value(s) in the table below.

   Standard voltage 

   TESTER CONNECTION AND SPECIFIED CONDITION TABLE
   
   

   Tester Connection	Condition	Specified Condition
   S12-2 - Body ground	Always	10 to 14 V

   Fig 2: Identifying S12 Stop Light Switch Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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.

   Standard resistance 

   TESTER CONNECTION AND SPECIFIED CONDITION TABLE
   
   

   Tester Connection	Condition	Specified Condition
   S12-1 - S12-2	Switch pin free	Below 1 Ω
   S12-1 - S12-2	Switch pin pushed in	10 kΩ or higher

   Fig 3: Identifying S12 Stop Light Switch Assembly Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE STOP LIGHT SWITCH ASSEMBLY 

OK: Go To Next Step 

1. Remove the stop light operation relay.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   TESTER CONNECTION AND SPECIFIED CONDITION TABLE
   
   

   Tester Connection	Condition	Specified Condition
   3 - 4	Always	Below 1 Ω

   Fig 4: Identifying Stop Light Operation Relay Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPLACE STOP LIGHT OPERATION RELAY 

OK: Go To Next Step 

1. Disconnect the skid control ECU connector.
2. Measure the resistance according to the value(s) in the table below.

   Standard resistance 

   TESTER CONNECTION AND SPECIFIED CONDITION TABLE
   
   

   Tester Connection	Condition	Specified Condition
   S28-7 (STP) - S12-1	Always	Below 1 Ω
   S28-7 (STP) - Body ground	Always	10 kΩ or higher

   HINT:

   • When troubleshooting in accordance with the DTC TABLE, check DTCs before replacing the master cylinder solenoid (See DTC CHECK/CLEAR  ).
   • When troubleshooting in accordance with PROBLEM SYMPTOMS TABLE , be sure to follow the table before replacing the master cylinder solenoid.
   Fig 5: Identifying Wire Harness Connector (Skid Control ECU - Stop Light Switch)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: REPLACE MASTER CYLINDER SOLENOID