SFI SYSTEM > ECM Power Source Circuit

for Preparation Click here


DESCRIPTION

When the power switch is turned on (IG), auxiliary battery voltage is applied to IGSW of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the coil, closing the contacts of the No. 2 integration relay (EFI MAIN relay) and supplying power to either terminal +B and +B2 of the ECM.

WIRING DIAGRAM


A231565E06


INSPECTION PROCEDURE

NOTICE:
  1. After turning the power switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work (Click here).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.

1.CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    D27-104 (E1) - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


2.INSPECT ECM (IGSW VOLTAGE)


    A194151E72

  1. Disconnect the ECM connector.

  1. Turn the power switch on (IG).

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A60-28 (IGSW) - Body ground
    		Power switch on (IG)
    		11 to 14 V

    Text in Illustration 
    *a
    		Front view of wire harness connector
    (to ECM)



NG
Go to step 7
OK


3.INSPECT NO. 2 INTEGRATION RELAY (EFI MAIN RELAY)

  1. Inspect the No. 2 integration relay (EFI MAIN relay) (Click here).



NG
REPLACE NO. 2 INTEGRATION RELAY (Click here)
OK


4.CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - ECM)

  1. Remove the No. 2 integration relay (EFI MAIN relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1B-4 - A60-1 (+B2)
    		Always
    		Below 1 Ω
    1B-4 - A60-2 (+B)
    		Always
    		Below 1 Ω
    1B-2 - A60-6 (MREL)
    		Always
    		Below 1 Ω
    1B-4 or A60-1 (+B2) - Body ground
    		Always
    		10 kΩ or higher
    1B-4 or A60-2 (+B) - Body ground
    		Always
    		10 kΩ or higher
    1B-2 or A60-6 (MREL) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - AUXILIARY BATTERY)

  1. Remove the No. 2 integration relay (EFI MAIN relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

  1. Disconnect the negative (-) auxiliary battery terminal.

  1. Disconnect the positive (+) auxiliary battery terminal.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1C-1 - Positive (+) auxiliary battery terminal
    		Always
    		Below 1 Ω
    1C-1 or Positive (+) auxiliary battery terminal - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)

  1. Remove the No. 2 integration relay (EFI MAIN relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1B-3 - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE (Click here)  

7.INSPECT NO. 2 INTEGRATION RELAY (IG2 RELAY)

  1. Inspect the No. 2 integration relay (IG2 relay) (Click here).



NG
REPLACE NO. 2 INTEGRATION RELAY (IG2 RELAY) (Click here)
OK


8.CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - ECM)

  1. Disconnect the ECM connector.

  1. Remove the No. 2 integration relay (IG2 relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1A-4 - A60-28 (IGSW)
    		Always
    		Below 1 Ω
    1A-4 or A60-28 (IGSW) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - AUXILIARY BATTERY)

  1. Remove the No. 2 integration relay (IG2 relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

  1. Disconnect the negative (-) auxiliary battery terminal.

  1. Disconnect the positive (+) auxiliary battery terminal.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1C-1 - Positive (+) auxiliary battery terminal
    		Always
    		Below 1 Ω
    1C-1 or Positive (+) auxiliary battery terminal - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


10.CHECK HARNESS AND CONNECTOR (NO. 2 INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)

  1. Remove the No. 2 integration relay (IG2 relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    1A-3 - Body ground
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


11.CHECK HARNESS AND CONNECTOR (POWER MANAGEMENT CONTROL ECU - INTEGRATION RELAY (IG2 RELAY))

  1. Remove the No. 2 integration relay (IG2 relay) from the engine room relay block.

  1. Disconnect the No. 2 integration relay connector.

  1. Disconnect the power management control ECU connector.

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

    Standard Resistance:

    Tester Connection
    		Condition
    		Specified Condition
    A20-2 (IG2D) - 1A-2
    		Always
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ENTRY AND START SYSTEM (FOR START FUNCTION) (Click here)