ECD SYSTEM (for CCo) > ECM Power Source Circuit

for Preparation Click here


DESCRIPTION

When the ignition switch is turned to ON, battery voltage is applied to terminal IGSW of the ECM. The output voltage from the MREL terminal of the ECM causes a current to flow to the coil of the EFI MAIN relay inside the integration relay, closing the contact of the EFI MAIN relay and supplying power to terminals +B and +B2 of the ECM.

WIRING DIAGRAM


A197106E04


INSPECTION PROCEDURE

NOTICE:
Inspect the fuses of circuits related to this system before performing the following inspection procedure.
1.CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - BATTERY)


    A209875E02

  1. Remove the integration relay from the engine room No. 1 relay block.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    Engine room relay block (1C-1) - Body ground
    		Always
    		11 to 14 V
    Text in Illustration 
    *1
    		Engine Room No. 1 Relay Block
    *2
    		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 MAIN RELAY)

  1. Inspect the EFI MAIN relay (Click here).



NG
REPLACE INTEGRATION NO.1 RELAY
OK


3.CHECK HARNESS AND CONNECTOR (+B, +B2 AND MREL CIRCUIT)
A209876E02

  1. Check the harness and connectors between the integration relay and ECM.

    1. Remove the integration relay from the engine room No. 1 relay block.

    2. Disconnect the ECM connector.

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

      Standard Resistance (Check for Open):
      Tester Connection
      		Condition
      		Specified Condition
      A12-45 (MREL) - 1A-2
      		Always
      		Below 1 Ω
      A12-1 (+B) - 1A-4
      		Always
      A12-20 (+B2) - 1A-4
      		Always

      Standard Resistance (Check for Short):
      Tester Connection
      		Condition
      		Specified Condition
      A12-45 (MREL) or 1A-2 - Body ground
      		Always
      		10 kΩ or higher
      A12-1 (+B) or 1A-4 - Body ground
      		Always
      A12-20 (+B2) or 1A-4 - Body ground
      		Always
      Text in Illustration 
      *1
      		Front view of wire harness connector
      (to ECM)
      *2
      		Engine Room No. 1 Relay Block
      *3
      		Front view of wire harness connector
      (to Integration Relay)

  1. Check the harness and connectors between the integration relay and body ground.

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

      Standard Resistance (Check for Open):
      Tester Connection
      		Condition
      		Specified Condition
      1A-3 - Body ground
      		Always
      		Below 1 Ω

  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)


    A204367E01

  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
    B32-109 (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 VOLTAGE)


    A130158E10

  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
    A12-25 (IGSW) - B32-109 (E1)
    		Ignition switch ON
    		11 to 14 V
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)
    *2
    		Front view of wire harness connector
    (to ECM)

  1. Reconnect the ECM connectors.



NG
Go to step 6
OK

REPLACE ECM (Click here)  

6.INSPECT RELAY (IG2 RELAY POWER SOURCE)
A209878E01

  1. Remove the IG2 relay from the engine room No. 1 relay block.

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

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    3 (IG2 relay holder) - Body ground
    		Always
    		11 to 14 V
    Text in Illustration 
    *1
    		Engine Room No. 1 Relay Block
    *2
    		IG2 Relay


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


7.INSPECT IG2 RELAY
B016200E02

  1. Remove the IG2 relay from the engine room No. 1 relay block.

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

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    3 - 5
    		Battery voltage not applied to terminals 1 and 2
    		10 kΩ or higher
    3 - 5
    		Battery voltage applied to terminals 1 and 2
    		Below 1 Ω

  1. Reinstall the relay.



NG
REPLACE IG2 RELAY
OK


8.CHECK HARNESS AND CONNECTOR (ECM - ENGINE ROOM NO. 1 RELAY BLOCK)
A209879E01

  1. Remove the IG2 relay from the engine room No. 1 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
    5 (IG2 relay holder) - A12-25 (IGSW)
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    5 (IG2 relay holder) or A12-25 (IGSW) - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to ECM)
    *2
    		Engine Room No. 1 Relay Block
    *3
    		IG2 Relay

  1. Reinstall the IG2 relay.

  1. Reconnect the ECM connector.

    Result 
    Result
    		Proceed to
    OK
    		A
    NG (w/ Entry and Start System)
    		B
    NG (w/o Entry and Start System)
    		C


B
Go to step 9

C
Go to step 10
A

REPAIR OR REPLACE HARNESS OR CONNECTOR 

9.CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - MAIN BODY ECU)
A209880E01

  1. Remove the IG2 relay from the engine room No. 1 relay block.

  1. Disconnect the main body 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
    1 (IG2 relay holder) - E19-5 (IG2D)
    		Always
    		Below 1 Ω
    2 (IG2 relay holder) - Body ground
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1 (IG2 relay holder) or E19-5 (IG2D) - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Main Body ECU)
    *2
    		Engine Room No. 1 Relay Block
    *3
    		IG2 Relay

  1. Reinstall the IG2 relay.

  1. Reconnect the main body ECU connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

CHECK ENTRY AND START SYSTEM (Click here)  

10.CHECK HARNESS AND CONNECTOR (ENGINE ROOM NO. 1 RELAY BLOCK - IGNITION SWITCH)
A210065E01

  1. Remove the IG2 relay from the engine room No. 1 relay block.

  1. Disconnect the ignition switch connector.

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

    Standard Resistance (Check for Open):
    Tester Connection
    		Condition
    		Specified Condition
    1 (IG2 relay holder) - E5-6 (IG2)
    		Always
    		Below 1 Ω
    2 (IG2 relay holder) - Body ground
    		Always
    		Below 1 Ω

    Standard Resistance (Check for Short):
    Tester Connection
    		Condition
    		Specified Condition
    1 (IG2 relay holder) or E5-6 (IG2) - Body ground
    		Always
    		10 kΩ or higher
    Text in Illustration 
    *1
    		Front view of wire harness connector
    (to Ignition Switch)
    *2
    		Engine Room No. 1 Relay Block
    *3
    		IG2 Relay

  1. Reinstall the IG2 relay.

  1. Reconnect the ignition switch connector.



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


11.INSPECT IGNITION SWITCH ASSEMBLY

  1. Inspect the ignition switch assembly (Click here).



NG
REPLACE IGNITION SWITCH ASSEMBLY (Click here)
OK

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