Inspection Procedure

HINT:

• Read freeze frame data using a Techstream. 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.
• STP signal conditions can be checked using the Techstream.
  1. Connect the Techstream to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the tester ON.
  4. Select the following menu items: Powertrain / Engine and ECT / All Data / Stop Light Switch.
  5. Check the STP signal when the brake pedal is depressed and released.

1. CHECK STOP LIGHT SWITCH ASSEMBLY (TERMINAL B VOLTAGE) 
   1. Disconnect the A13 stop light switch connector.
   Fig 1: Identifying Stop Light Switch Connector Terminals
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Turn the ignition switch to ON.
   3. Measure the voltage between the terminals of the A13 stop light switch connector and body ground.

      Standard voltage 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Specified Conditions
      B (A13-2) - Body ground	11 to 14 V
      B (A13-3) - Body ground

   4. Reconnect the stop light switch connector.

   NG:  Go to step  4

   OK: Go to Next Step 

2. INSPECT STOP LIGHT SWITCH ASSEMBLY 
   1. Remove the stop light switch assembly.
   Fig 2: Identifying Stop Light Switch Assembly
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Check the resistance.

      Standard resistance 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

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

   3. Reinstall the stop light switch assembly.

   NG: REPLACE STOP LIGHT SWITCH ASSEMBLY  (See REMOVAL )

   OK: Go to Next Step 

3. INSPECT ECM (STP AND ST1 - VOLTAGE) 
   Fig 3: Identifying ECM (STP And ST1 - Voltage)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Disconnect the A21 ECM connector.
   2. Turn the ignition switch to ON.
   3. Measure the voltage between the terminals ST1- and STP of the A21 ECM connector and body ground.

      Standard voltage 

      TESTER CONNECTIONS SPECIFIED CONDITIONS CHART
      
      

      Tester Connections	Brake Pedal Operations	Specified Conditions
      ST1- (A21-35) - Body ground	Released	11 to 14 V
      	Depressed	0 to 3 V
      STP (A21-36)- Body ground	Released	0 to 3 V
      	Depressed	11 to 14 V

   4. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE ECM (See  REMOVAL   ) 

4. INSPECT FUSE (STOP AND IGN FUSE) 
   1. Remove the STOP and IGN fuses from the main body ECU.
   Fig 4: Identifying Stop And IGN Fuses In Main Body ECU
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   2. Check the resistance.

      Standard resistance: Below 1 Ω 

   3. Reinstall the STOP and IGN fuses.

   NG: CHECK FOR SHORTS IN ALL HARNESSES AND CONNECTORS CONNECTED TO FUSE AND REPLACE FUSE 

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR