Inspection Procedure

HINT:

When troubleshooting in accordance with the PROBLEM SYMPTOMS TABLE, be sure to follow the table before replacing the ECM.

1. INSPECT STOP LIGHT SWITCH ASSEMBLY 
   1. Disconnect the S8 stop light switch connector.
   2. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      RESISTANCE REFERENCE
      
      

      Tester Connection	Condition	Specified Condition
      1 - 2	Switch pin free	Below 1 Ω
      3 - 4	Switch pin free	10 kΩ or higher
      1 - 2	Switch pin pushed in	10 kΩ or higher
      3 - 4	Switch pin pushed in	Below 1 Ω

   Fig 1: Identifying Stop Light Switch Assembly
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPLACE STOP LIGHT SWITCH ASSEMBLY 

   OK: Go to next step 

2. CHECK WIRE HARNESS (STOP LIGHT SWITCH - BATTERY) 
   1. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      2 - Body ground	Always	10 to 14 V
      3 - Body ground	Ignition switch ON	10 to 14 V

   Fig 2: Identifying S8 Connector Terminal
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

   OK: Go to next step 

3. CHECK WIRE HARNESS (ECM - STOP LIGHT SWITCH) 
   1. Reconnect the S8 stop light switch connector.
   2. Disconnect the E4 and E5 connectors from the ECM.
   3. Turn the ignition switch to the ON position.
   4. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      VOLTAGE SPECIFICATION
      
      

      Tester Connection	Condition	Specified Condition
      E4-16 (ST1-) - Body ground	Brake pedal depressed	Below 1 V
      E4-16 (ST1-) - Body ground	Brake pedal released	10 to 14 V
      E5-4 (STP) - Body ground	Brake pedal depressed	10 to 14 V
      E5-4 (STP) - Body ground	Brake pedal released	Below 1 V

   Fig 3: Identifying E4 And E5 Connectors Of ECM
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

   OK: REPLACE ECM