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SFI SYSTEM (w/ EGR System) > ECM Power Source Circuit

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DESCRIPTION

When the power switch is turned on (IG), 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 integration relay (EFI MAIN relay) and supplying power to either terminal +B and +B2 of the ECM.

WIRING DIAGRAM


A217616E01


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses for circuits related to this system before performing the following inspection procedure.

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


    A194154E52

  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
    D28-104 (E1) - Body ground
    		Always
    		Below 1 Ω

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (ECM - BODY GROUND)
OK


2.INSPECT ECM (IGSW VOLTAGE)


    A194151E25

  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
    A57-28 (IGSW) - Body ground
    		Power switch on (IG)
    		11 to 14 V

    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the ECM connector.



NG
Go to step 7
OK


3.INSPECT INTEGRATION RELAY (EFI MAIN RELAY)


    A172755E06

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the integration relay connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1C-1 - 1B-4
    		No battery voltage applied between terminals 1B-2 and 1B-3
    		10 kΩ or higher
    Battery voltage applied between terminals 1B-2 and 1B-3
    		Below 1 Ω

    Text in Illustration 
    *1
    		Component without harness connected
    (Integration Relay)

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.



NG
REPLACE INTEGRATION RELAY (Click here)
OK


4.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - ECM)


  1. Remove the integration relay from the engine room relay block.


    A217617E01

  1. Disconnect the integration relay connector.

  1. Disconnect the ECM connector.

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    1B-4 - A57-1 (+B2)
    		Always
    		Below 1 Ω
    1B-4 - A57-2 (+B)
    		Always
    		Below 1 Ω
    1B-2 - A57-6 (MREL)
    		Always
    		Below 1 Ω


    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    1B-4 or A57-1 (+B2) - Body ground
    		Always
    		10 kΩ or higher
    1B-4 or A57-2 (+B) - Body ground
    		Always
    		10 kΩ or higher
    1B-2 or A57-6 (MREL) - Body ground
    		Always
    		10 kΩ or higher


    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)
    		*2
    		Integration Relay
    *3
    		Front view of wire harness connector
    (to Integration Relay)
    		-
    		-

  1. Reconnect the ECM connector.

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - ECM)
OK


5.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - BATTERY)


    A217618E01

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the integration relay connector.

  1. Disconnect the negative battery terminal.

  1. Disconnect the positive battery terminal.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    1C-1 - Battery positive terminal
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1C-1 or Battery positive terminal - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Integration Relay
    *2
    		Front view of wire harness connector
    (to Integration Relay)

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.

  1. Reconnect the positive battery terminal.

  1. Reconnect the negative battery terminal.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - BATTERY)
OK


6.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)


    A217619E01

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the 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

    Text in Illustration 
    *1
    		Integration Relay
    *2
    		Front view of wire harness connector
    (to Integration Relay)

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY (EFI MAIN RELAY) - BODY GROUND)
OK

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

7.INSPECT INTEGRATION RELAY (IG2 RELAY)


    A172755E07

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the integration relay connector.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    1C-1 - 1A-4
    		No battery voltage applied to terminals 1A-2 and 1A-3
    		10 kΩ or higher
    Battery voltage applied to terminals 1A-2 and 1A-3
    		Below 1 Ω

    Text in Illustration 
    *1
    		Component without harness connected
    (Integration Relay)

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.



NG
REPLACE INTEGRATION RELAY (IG2 RELAY) (Click here)
OK


8.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - ECM)


  1. Disconnect the ECM connector.


    A217620E01

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the integration relay connector.

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

    Standard Resistance (Check for Open):

    Tester Connection
    		Condition
    		Specified Condition
    1A-4 - A57-28 (IGSW)
    		Always
    		Below 1 Ω


    Standard Resistance (Check for Short):

    Tester Connection
    		Condition
    		Specified Condition
    1A-4 or A57-28 (IGSW) - Body ground
    		Always
    		10 kΩ or higher


    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)
    		*2
    		Integration Relay
    *3
    		Front view of wire harness connector
    (to Integration Relay)
    		-
    		-

  1. Reconnect the ECM connector.

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - ECM)
OK


9.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BATTERY)


    A217618E01

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the integration relay connector.

  1. Disconnect the negative battery terminal.

  1. Disconnect the positive battery terminal.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    1C-1 - Battery positive terminal
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1C-1 or Battery positive terminal - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Integration Relay
    *2
    		Front view of wire harness connector
    (to Integration Relay)



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BATTERY)
OK


10.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)


    A217622E01

  1. Remove the integration relay from the engine room relay block.

  1. Disconnect the 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

    Text in Illustration 
    *1
    		Integration Relay
    *2
    		Front view of wire harness connector
    (to Integration Relay)

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (INTEGRATION RELAY (IG2 RELAY) - BODY GROUND)
OK


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


  1. Remove the integration relay from the engine room relay block.


    A217623E01

  1. Disconnect the 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
    A22-2 (IG2D) - 1A-2
    		Always
    		Below 1 Ω


    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Power Management Control ECU)
    		*2
    		Integration Relay
    *3
    		Front view of wire harness connector
    (to Integration Relay)
    		-
    		-

  1. Reconnect the integration relay connector.

  1. Reinstall the integration relay.

  1. Reconnect the power management control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER MANAGEMENT CONTROL ECU - INTEGRATION RELAY (IG2 RELAY))
OK

CHECK ENTRY AND START SYSTEM (Click here)