Inspection Procedure

1. Connect Techstream to the DLC3.
2. Turn the engine switch ON (IG) and press Techstream main switch on.
3. Read the Data List according to the displays on the tester.

   Power Source Control ECU: 

   DIAGNOSTIC NOTE CHART
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Engine Condition	Engine condition / RUN or STOP	RUN: Engine switch is ON (START) STOP: Engine switch is OFF, ON (IG) or ON (ACC)	-

   OK: "RUN" (engine switch is on (START)) appears on the screen. 

   "STOP" (engine switch is off, on (IG) or on (ACC)) appears on the screen. 

NG: Go to step 2 

OK:  Go to SFI SYSTEM

1. Disconnect the D44 ECU connector.
   Fig 1: Disconnecting D44 ECU Connector

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the A55 ECM connector.
3. Measure the resistance according to the value(s) in the table below.

   Resistance 

   TESTER CONNECTION SPECIFIED CONDITION CHART
   
   

   Tester Connection	Specified Condition
   D44-2 (TACH) - A55-15 (TACH)	Below 1 Ω
   D44-2 (TACH) - Body ground	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

Fig 2: Identifying A55 ECM Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

OK: Go to next step 

1. After replacing the power source control ECU with a normally functioning ECU, check for power source control ECU DTCs.

   OK: Power source control ECU DTCs are not output. 

NG:  GO TO SFI SYSTEM

OK : END (POWER SOURCE CONTROL ECU DEFECTIVE)