Engine Switch Indicator Circuit: Procedure

Fig 1: Identifying Terminals Of Engine Switch Connector

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 light does not illuminate.
   • If the voltage is too low, the indicator light will not illuminate.

   OK

   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.
   Fig 2: Identifying Terminals Of K73 Power Source Control ECU And K29 Of Engine Switch Connectors

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the K73 ECU connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance

   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 

OK → REPLACE POWER SOURCE CONTROL ECU