Engine Switch Indicator Circuit: Procedure

WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

INSPECT ENGINE SWITCH

Disconnect the D21 switch connector.

Fig 1: Identifying D21 Switch Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
Connect the positive (+) lead to terminal "A" and the negative (-) lead to terminal "B" of the engine switch.

Check if the illumination for the engine switch comes on.

Positive (+) Connection (Symbols)	Negative (-) Connection (Symbols)	Illumination Condition
D21-11 (SWIL)	D21-4 (COM) or D21-5 (GND)	Comes on
D21-12 (INDS)	D21-4 (COM) or D21-5 (GND)	Comes on
D21-13 (INDW)	D21-4 (COM) or D21-5 (GND)	Comes on

NG → REPLACE ENGINE SWITCH

OK: Go to next step

CHECK WIRE HARNESS (ENGINE SWITCH - POWER SOURCE CONTROL ECU AND BODY GROUND)

Disconnect the D44 ECU connector.

Fig 2: Identifying D44 ECU Connector Terminals
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Measure the resistance according to the value(s) in the table below.

Fig 3: Identifying Engine Switch Connector Terminals

Resistance

Tester Connection (Symbols)	Condition	Specified condition
D44-4 (INDS) - D21-12 (INDS)	Always	Below 1 Ω
D44-13 (INDW) - D21-13 (INDW)	Always	Below 1 Ω
D44-36 (SWIL) - D21-11 (SWIL)	Always	Below 1 Ω
D44-4 (INDS) - Body ground	Always	1 MΩ or Higher
D44-13 (INDW) - Body ground	Always	1 MΩ or Higher
D44-36 (SWIL) - Body ground	Always	1 MΩ or Higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK → REPLACE POWER SOURCE CONTROL ECU