Engine Switch Indicator Circuit: Procedure

1. Remove the engine switch. Refer to REMOVAL .
   Fig 1: Inspecting Engine Switch Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
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 will not illuminate.
   • If the voltage is too low, the indicator 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 → See step   3 

OK: Go to next step 

1. Disconnect the E38 switch connector.
   Fig 2: Identifying Main Body ECU And E38 Switch Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the E51 and E52 ECU connectors.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   E38-11 (SWIL) - E51-8 (SWIL)	Always	Below 1 Ω
   E38-12 (INDS) - E52-1 (INDS)
   E38-13 (INDW) - E52-8 (INDW)
   E38-5 (GND) - Body ground
   E38-4 (COM) - Body ground
   E38-11 (SWIL) or E51-8 (SWIL) - Body ground		10 kΩ or higher
   E38-12 (INDS) or E52-1 (INDS) - Body ground
   E38-13 (INDW) or E52-8 (INDW) - Body ground

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

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