SFI SYSTEM ECM Power Source Circuit

DESCRIPTION

When the engine switch is turned on (IG), battery voltage is applied to the 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) and supplying power to either terminal +B or +B2 of the ECM.

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   INSPECT INTEGRATION RELAY (INTEGRATION RELAY - BODY GROUND)

   
   

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

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

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

   
   
   • OKClick here
   • NGClick here
2. Click here

   INSPECT INTEGRATION RELAY (EFI AND IG2 RELAY)

   
   

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

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1C-1 - 1B-4 Battery voltage is not applied to terminals 1B-2 and 1B-3 10 kΩ or higher Battery voltage is applied to terminals 1B-2 and 1B-3 Below 1 Ω 1C-1 - 1B-8 Battery voltage is not applied to terminals 1B-7 and 1B-6 10 kΩ or higher Battery voltage is applied to terminals 1B-7 and 1B-6 Below 1 Ω

   
   
   • OKClick here
   • NGClick here
3. Click here

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

   
   

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

      
      

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

      2. Disconnect the ECM connector.

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

         Standard Resistance
         Tester Connection Condition Specified Condition A38-34 (MREL) - 1B-2 Always Below 1 Ω A38-3 (+B) - 1B-4 Always Below 1 Ω A38-2 (+B2) - 1B-4 Always Below 1 Ω A38-34 (MREL) or 1B-2 - Body ground Always 10 kΩ or higher A38-3 (+B) or 1B-4 - Body ground Always 10 kΩ or higher A38-2 (+B2) or 1B-4 - Body ground Always 10 kΩ or higher

   2. 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
         Tester Connection Condition Specified Condition 1B-3 - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NGClick here
4. Click here

   CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

   
   

   1. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition C45-81 (E1) - Body ground Always Below 1 Ω

   
   
   • OKClick here
   • NGClick here
5. Click here

   INSPECT ECM (IGSW VOLTAGE)

   
   

   1. Disconnect the ECM connectors.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition A38-28 (IGSW) - C45-81 (E1) Engine switch on (IG) 11 to 14 V

   
   
   • OKClick here
   • NGClick here
6. Click here

   CHECK HARNESS AND CONNECTOR (INTEGRATION RELAY - ECM, INTEGRATION RELAY - BODY GROUND)

   
   

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

   2. Disconnect the ECM connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition 1B-8 - A38-28 (IGSW) Always Below 1 Ω 1B-8 or A38-28 (IGSW) - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NGClick here
7. Click here

   CHECK HARNESS AND CONNECTOR (MAIN BODY ECU - ENGINE ROOM RELAY BLOCK)

   
   

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

   2. Disconnect the E2 main body ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition E2-11 (IG2D) - 1B-6 Always Below 1 Ω E2-11 (IG2D) or 1B-6 - Body ground Always 10 kΩ or higher

   
   
   • OKClick here
   • NGClick here
8. Click here

   CHECK ENTRY AND START SYSTEM (POWER SOURCE MODE DOES NOT CHANGE)

   
   

   1. Check the entry and start system (Click here).

   
   
   • OKClick here
   • NGClick here
9. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR

10. Click here

    REPLACE INTEGRATION RELAY

11. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

12. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

13. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

14. Click here

    REPAIR OR REPLACE HARNESS OR CONNECTOR

15. Click here

    REPAIR ENTRY AND START SYSTEM

16. Click here

    REPLACE ECMClick here