Security Indicator Light Circuit: Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch to the ON position.
3. Turn the Techstream main switch on.
4. Select the item below in the Active Test and then check that the indicator operates.
   MAIN BODY:
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Security Indicator	Security indicator	ON / OFF	-

   OK

   The security indicator light flashes or goes off correctly when operating it through Techstream.

NG → See step   2 

OK → See step   5 

1. Disconnect the D10 ECU connector.
   Fig 1: Identifying D76 Connector Security Indicator Light & D10 ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D76 connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D10-4 (IND) - D76-2 (LP)	Always	Below 1 Ω
   D10-4 (IND) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Measure the resistance according to the value(s) in the table below.
   Fig 2: Identifying Security Indicator Light Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D76-1 (E) - Body ground	Always	Below 1 Ω

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the D76 connector with the D10 ECU connector still disconnected.
   Fig 3: Identifying Security Indicator Light Connector Terminal

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Apply battery voltage from the wire harness back side between the specified terminals of the indicator, and check the lighting condition of the security indicator.

   Standard

   Measurement Condition	Specified Condition
   Battery positive (+) → Terminal D76-2 (LP) Battery negative (-) → Terminal D76-1 (E)	Security indicator comes on

   NOTE:

   • If the positive (+) lead and the negative (-) lead are incorrectly connected, the security indicator will not come on.
   • Voltage of more than 12 V will damage the security indicator.
   • If the voltage is too low, the security indicator will not come on.

NG → See step   6 

OK → REPLACE MAIN BODY ECU (INSTRUMENT PANEL JUNCTION BLOCK)