SFI SYSTEM > ECM Power Source Circuit

for Preparation Click here


DESCRIPTION

When the ignition switch is turned ON, the battery voltage is applied to the IGSW terminal of the ECM. The output signal from the MREL terminal of the ECM causes a current to flow to the EFI relay coil, closing the EFI relay contacts and supplying power to terminal +B of the ECM.

WIRING DIAGRAM


A201218E02


INSPECTION PROCEDURE

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

1.INSPECT INTEGRATION NO.1 RELAY (POWER SOURCE)
A201293E01

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

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    1A-1 - Body ground
    		Always
    		11 to 14 V

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

  1. Reinstall the integration relay.



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


2.INSPECT INTEGRATION NO.1 RELAY (EFI RELAY AND IG2 RELAY)
A200843E01

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

  1. Inspect the relay

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

      Standard Resistance:
      Tester Connection
      		Condition
      		Specified Condition
      1A-1 - 1B-4 or 1B-10
      		When battery voltage absent
      		10 kΩ or higher
      When battery voltage applied to terminals 1B-2 and 1C-3
      		Below 1 Ω
      1A-1 - 1B-7
      		When battery voltage absent
      		10 kΩ or higher
      When battery voltage applied to terminals 1C-3 and 1D-11
      		Below 1 Ω

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

  1. Reinstall the integration relay.



NG
REPLACE INTEGRATION NO.1 RELAY (Click here)
OK


3.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM)
A201294E01

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

  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
    A18-44 (MREL) - 1B-2
    		Always
    		Below 1 Ω
    A18-2 (+B) - 1B-10
    		Always
    		Below 1 Ω
    A18-1 (+B2) - 1B-4
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    A18-44 (MREL) or 1B-2 - Body ground
    		Always
    		10 kΩ or higher
    A18-2 (+B) or 1B-10 - Body ground
    		Always
    		10 kΩ or higher
    A18-1 (+B2) or 1B-4 - Body ground
    		Always
    		10 kΩ or higher

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

  1. Reinstall the integration relay.

  1. Reconnect the ECM connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)
A159981E15

  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
    B8-105 (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
OK


5.INSPECT ECM (IGSW TERMINAL VOLTAGE)
A201350E01

  1. Disconnect the ECM connectors.

  1. Turn the ignition switch to ON.

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

    Standard Voltage:
    Tester Connection
    		Switch Condition
    		Specified Condition
    A18-27 (IGSW) - B8-105 (E1)
    		Ignition switch ON
    		11 to 14 V

  1. Reconnect the ECM connectors.

Result 
Result
Proceed to
Outside standard range
A
Within standard range
B
Text in Illustration 
*1
Front view of wire harness connector:
(to ECM)
*2
Front view of wire harness connector:
(to ECM)


B
REPLACE ECM (Click here)
A


6.CHECK HARNESS AND CONNECTOR (ECM - INTEGRATION RELAY)
A201294E02

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

  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
    A18-27 (IGSW) - 1B-7
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    A18-27 (IGSW) or 1B-7 - Body ground
    		Always
    		10 kΩ or higher

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

  1. Reinstall the integration relay.

  1. Reconnect the ECM connector.
    Result 
    Result
    		Proceed to
    Outside normal range
    		A
    Within normal range (w/ Entry and Start System)
    		B
    Within normal range (w/o Entry and Start System)
    		C



B
Go to step 7

C
Go to step 8
A

REPAIR OR REPLACE HARNESS OR CONNECTOR 

7.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - POWER MANAGEMENT CONTROL ECU - BODY GROUND)
A201357E01

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

  1. Disconnect the power management control ECU connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    1D-11 - D36-8 (IG2D)
    		Always
    		Below 1 Ω
    1C-3 - Body ground
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1D-11 or D36-8 (IG2D) - Body ground
    		Always
    		10 kΩ or higher

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

  1. Reinstall the integration relay.

  1. Reconnect power management control ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ENTRY AND START SYSTEM (Click here)  

8.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - IGNITION SWITCH - BODY GROUND)
A201295E01

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

  1. Disconnect the ignition switch assembly connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    1D-11 - D28-6 (IG2)
    		Always
    		Below 1 Ω
    1C-3 - Body ground
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1D-11 or D28-6 (IG2) - Body ground
    		Always
    		10 kΩ or higher

    Text in Illustration 
    *1
    		Front view of wire harness connector:
    (to Integration Relay)
    *2
    		Front view of wire harness connector:
    (to Integration Relay)
    *3
    		Front view of wire harness connector:
    (to Ignition Switch Assembly)

  1. Reinstall the integration relay.

  1. Reconnect the ignition switch assembly connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


9.INSPECT IGNITION SWITCH ASSEMBLY
A203952E02

  1. Remove the ignition assembly switch.

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

    Standard Resistance:
    Tester Connection
    		Switch Condition
    		Specified Condition
    -
    		LOCK
    		10 kΩ or higher
    2 - 3
    		ACC
    		Below 1 Ω
    2 - 3- 4
    		ON
    6 - 7
    1 - 2- 4
    		START
    6 - 7 - 8

  1. Reinstall the ignition switch assembly.



NG
REPLACE IGNITION SWITCH ASSEMBLY
OK

REPAIR OR REPLACE HARNESS OR CONNECTOR (IGNITION SWITCH - BATTERY)