Inspection Procedure

HINT:

Read freeze frame data using the Techstream. The ECM records vehicle and driving condition information as freeze frame data the moment a DTC is stored. When troubleshooting, freeze frame data can be helpful in determining whether the vehicle was running or stopped, whether the engine was warmed up or not, whether the air/fuel ratio was lean or rich, as well as other data recorded at the time of a malfunction.

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

      OK: Stop light turns 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 
   1. Check the stop light switch (See STOP LIGHT SWITCH ).

   NG: REPLACE STOP LIGHT SWITCH ASSEMBLY 

   OK: Go to Next Step 

3. READ VALUE OF TECHSTREAM (STP SIGNAL AND ST1- VOLTAGE) 
   1. Connect the Techstream to the DLC3.
   2. Turn the ignition switch ON.
   3. Enter the following menus: Powertrain/Engine and ECT/All Data/Stop Light Switch.
   4. Confirm the stop light switch status when the brake pedal is depressed and released.

      OK 

      BRAKE PEDAL CONDITION
      
      

      Brake Pedal Condition	Specified Condition
      Depressed	STP Signal ON
      Released	STP Signal OFF

   5. Measure the voltage of the ECM when the brake pedal is depressed and released.
      Fig 1: Reading Value Of Techstream (STP Signal And ST1- Voltage)

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard voltage 

      STANDARD VOLTAGE
      
      

      Tester Connection	Brake Pedal Condition	Specified Condition
      ST1- (E9-16) - E1 (E7-1)	Depressed	Below 1.5 V
      ST1- (E9-16) - E1 (E7-1)	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 S17 stop light switch connector.
   2. Disconnect the E9 ECM connector
   3. Measure the resistance between the wire harness side connectors.

      Standard resistance (Check for open) 

      STANDARD RESISTANCE
      
      

      Tester Connection	Specified Condition
      Stop light switch (S17-1) - STP (E9-15)	Below 1 Ω
      Stop light switch (S17-4) - ST1- (E9-16)

      Standard resistance (Check for short) 

      STANDARD RESISTANCE
      
      

      Tester Connection	Specified Condition
      Stop light switch (S17-1) or STP (E9-15) - Body ground	10 kΩ or higher
      Stop light switch (S17-4) or ST1- (E9-16) - Body ground

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

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   Fig 2: Checking Harness And Connector (Stop Light Switch - ECM)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK: REPLACE ECM