Engine Switch Illumination Circuit: Procedure

1. Connect Techstream to the DLC3.
2. Turn the ignition switch on (IG).
3. Turn Techstream on.
4. Select the following menu items: Body Electrical / Main Body / Active Test.
5. Check the operation.
   MAIN BODY:
   
   

   Tester Display	Test Part	Control Range	Diagnostic Note
   Indicator for Lighting	Engine switch illumination	ON / OFF	-

   OK

   Engine switch illumination comes on.

NG → See step   2 

OK → See step   4 

1. Remove the engine switch.
   Fig 1: Checking Engine Switch For Illumination

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Apply battery voltage to the engine switch.
3. Check that the illumination comes on.

   OK

   Measurement Condition	Specified Condition
   Battery positive (+) → Terminal 11 (SWIL) Battery negative (-) → Terminal 5 (GND) or 4 (COM)	Engine switch illumination comes on

NG → REPLACE ENGINE SWITCH 

OK: Go to next step 

1. Disconnect the D8 main body ECU connector.
   Fig 2: Checking Harness And Connector (Engine Switch - Main Body ECU And Body Ground)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the D25 engine switch connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard resistance

   Tester Connection	Condition	Specified Condition
   D25-11 (SWIL) - D8-25 (SWIL)	Always	Below 1 Ω
   D25-4 (COM) or D25-5 (GND) - Body ground	Always	Below 1 Ω
   D25-11 (SWIL) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

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