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.
• STP signal conditions can be checked using an intelligent tester.
  1. Connect the intelligent tester to the DLC3.
  2. Turn the ignition switch to ON.
  3. Turn the tester ON.
  4. Select the following menu items: DIAGNOSIS / ENHANCED OBD II / DATA LIST / PRIMARY / STOP LIGHT SW.
  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.
   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 

      VOLTAGE SPECIFICATION
      
      

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

      Fig 1: Identifying A13 Stop Light Switch Connector

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   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.
   2. Check the resistance. Standard resistance
      RESISTANCE SPECIFICATION
      
      

      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

      Fig 2: Inspecting Stop Light Switch Assembly

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   3. Reinstall the stop light switch assembly.

   NG: REPLACE STOP LIGHT SWITCH ASSEMBLY 

   OK: GO TO NEXT STEP 

3. CHECK ECM (STP AND ST1 - VOLTAGE) 
   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 

      VOLTAGE SPECIFICATION
      
      

      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

      Fig 3: Depressing & Releasing Brake Pedal

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   4. Reconnect the ECM connector.

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

   OK: REPLACE ECM 

4. INSPECT FUSE (STOP AND IGN FUSE) 
   1. Remove the STOP and IGN fuses from the main body ECU.
   2. Check the resistance.

      Standard resistance: 

      Below 1 Ω 

   3. Reinstall the STOP and IGN fuses.
      Fig 4: Identifying STOP & IGN Fuse

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

   OK: REPAIR OR REPLACE HARNESS OR CONNECTOR