Inspection Procedure

1. Check the DATA LIST for proper functioning of the engine condition.

   Power source control ECU 

   DATA LIST
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Ready Signal	READY condition / ON or OFF or UNKNOWN	ON: Power switch ON (READY) OFF: Power switch ON (IG) / (READY OFF) UNKNOWN: Power switch OFF	-

   OK: ON (engine (hybrid) running) appears on screen. 

OK: REPLACE POWER SOURCE CONTROL ECU 

NG: Go to Next Step 

1. Disconnect the K73 ECU connector.
2. Disconnect the A54 ECU connector.
3. Measure the resistance of the wire harness side connectors.

   Standard resistance 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   K73-22 (RDY) - A54-117 (RDY)	Below 1 Ω
   K73-22 (RDY) or A54-117 (RDY) - Body ground	10 kΩ or higher

Fig 1: Identifying Terminals Of K73 And A54 ECU Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to Next Step 

1. Measure the voltage of the power source control ECU.

   Standard voltage 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Condition	Specified Condition
   22 (RDY) - Body ground	Power switch ON (IG) or ON (READY)	Pulse generation (see TERMINALS OF ECU  )

Fig 2: Identifying Terminals Of Power Source Control ECU Connector
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

NG:  GO TO HYBRID CONTROL SYSTEM

OK: REPLACE POWER SOURCE CONTROL ECU