Inspection Procedure

HINT:

Read freeze frame data using an intelligent tester. Freeze frame data record the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data, from the time the malfunction occurred.

1. CHECK OPERATION OF STOP LIGHT 
   1. Check whether the stop lights turn on and off normally when the brake pedal is depressed and released.

      OK: 

      Stop lights turn ON when brake pedal is depressed. 

   NG: REPAIR OR REPLACE STOP LIGHT SWITCH CIRCUIT 

   OK: Go TO NEXT STEP 

2. INSPECT STOP LIGHT SWITCH ASSEMBLY 
   Fig 1: Identifying Stop Light Switch Assembly

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the stop light switch assembly.
   2. Check the resistance.

      Standard Resistance 

      STANDARD RESISTANCE SPECIFICATIONS
      
      

      Switch Positions	Tester Connections	Specified Conditions
      Switch pin free	1 - 2	Below 1 Ω
      	3 - 4	10 kΩ or higher
      Switch pin pushed In	1 - 2	10 kΩ or higher
      	3 - 4	Below 1 Ω

   3. Reinstall the stop light switch assembly.

   NG: REPLACE STOP LIGHT SWITCH ASSEMBLY 

   OK: Go TO NEXT STEP 

3. READ VALUE USING INTELLIGENT TESTER (STP SIGNAL AND ST1- VOLTAGE) 
   1. Connect an intelligent tester to the DLC3.
   2. Turn the ignition switch ON and turn the tester ON.
   3. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / STOP LIGHT SW.
   4. Check the STP signal when the brake pedal is depressed and released.
      Fig 2: Identifying Brake Pedal Position

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard 

      BRAKE PEDAL SPECIFICATIONS
      
      

      Brake Pedal Operations	Specified Conditions
      Depressed	STP signal ON
      Released	STP signal OFF

   5. Measure the voltage between the terminals of the B3 and E47 ECM connectors.

      Standard Voltage 

      STANDARD VOLTAGE SPECIFICATIONS
      
      

      Tester Connections	Brake Pedal Operations	Specified Conditions
      ST1- (E47-16) - E1 (B3-1)	Depressed	Below 1.5 V
      	Released	7.5 to 14 V

   OK: CHECK FOR INTERMITTENT PROBLEMS 

   NG: Go TO NEXT STEP 

4. CHECK HARNESS AND CONNECTOR (STOP LIGHT SWITCH - ECM) 
   1. Disconnect the A3 stop light switch connector.
   2. Disconnect the E47 ECM connector.
      Fig 3: Identifying A3 Stop Light Switch Connector & E47 ECM Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Check the resistance.

      Standard Resistance (Check for open) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      Stop light switch (A3-1) - STP (E47-15)	Below 1 Ω
      Stop light switch (A3-4) - ST1- (E47-16)

      Standard Resistance (Check for short) 

      TESTER CONNECTIONS AND SPECIFIED CONDITIONS
      
      

      Tester Connections	Specified Conditions
      Stop light switch (A3-1) or STP (E47-15) - Body ground	10 kΩ or higher
      Stop light switch (A3-4) or ST1 - (E47-16) - Body ground

   4. Reconnect the stop light switch connector.
   5. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE ECM  (See REMOVAL  )