Engine Switch Indicator Circuit: Wiring Diagram

Fig 2: Inspecting Engine Switch

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Remove the engine switch.
2. Apply battery voltage between the terminals of the switch, and check the illumination condition of the switch.
   NOTE:

   • If the positive (+) lead and the negative (-) lead are incorrectly connected, the engine switch indicator does not illuminate.
   • If the voltage is too low, the indicator will not illuminate.

   OK 

   VOLTAGE MEASUREMENT CHART
   
   

   Measurement Condition	Specified Condition
   Battery positive (+) --> Terminal 11 (SWIL) Battery negative (-) --> Terminal 4 (COM) or 5 (GND)	Illuminates
   Battery positive (+) --> Terminal 12 (INDS) Battery negative (-) --> Terminal 4 (COM) or 5 (GND)	Illuminates
   Battery positive (+) --> Terminal 13 (INDW) Battery negative (-) --> Terminal 4 (COM) or 5 (GND)	Illuminates

NG : REPLACE ENGINE SWITCH 

OK : GO TO NEXT STEP. 

1. Disconnect the K29 switch connector.
2. Disconnect the K73 ECU connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   STANDARD RESISTANCE DESCRIPTION
   
   

   Tester Connection	Specified Condition
   K29-11 (SWIL) - K73-36 (SWIL)	Below 1 Ω
   K29-12 (INDS) - K73-4 (INDS)	Below 1 Ω
   K29-13 (INDW) - K73-13 (INDW)	Below 1 Ω
   K29-5 (GND) - Body ground	Below 1 Ω
   K29-4 (COM) - Body ground	Below 1 Ω
   K29-11 (SWIL) or K73-36 (SWIL) - Body ground	10 kΩ or higher
   K29-12 (INDS) or K73-4 (INDS) - Body ground	10 kΩ or higher
   K29-13 (INDW) or K73-13 (INDW) - Body ground	10 kΩ or higher

NG : REPAIR OR REPLACE HARNESS AND CONNECTOR 

Fig 3: Identifying Wire Harness (Engine Switch - Power Source Control ECU And Body Ground)

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK : REPLACE POWER SOURCE CONTROL ECU