СИСТЕМА ECD ECM Power Source Circuit

DESCRIPTION

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

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   INSPECT ECM TERMINAL VOLTAGE (+B TERMINAL)

   
   
   1. 

      Turn the ignition switch ON.

   2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition B9-1 (+B) - D3-7 (E1) 9 to 14 V

   
   
   • NGClick here
   • OKClick here
2. Click here

   CHECK HARNESS AND CONNECTOR (ECM - BODY GROUND)

   
   
   1. 

      Disconnect the D3 ECM connector.

   2. Measure the resistance of the wire harness side connector.

      Standard resistance
      Tester Connection Specified Condition D3-7 (E1) - Body ground Below 1 Ω

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK ECM TERMINAL VOLTAGE (IGSW TERMINAL)

   
   
   1. 

      Turn the ignition switch ON.

   2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition B9-9 (IGSW) - D3-7 (E1) 9 to 14 V

   
   
   • NGClick here
   • OKClick here
4. Click here

   INSPECT FUSE (IGN FUSE)

   
   
   1. 

      Remove the IGN fuse from the instrument panel J/B.

   2. Measure the resistance of the fuse.

      Standard resistance
      Below 1 Ω

   
   
   • OKClick here
   • NGClick here
5. Click here

   INSPECT IGNITION SWITCH ASSEMBLY

   
   
   1. 

      Disconnect the ignition switch connector.

   2. Measure the resistance of the ignition switch.

      Standard resistance
      Tester Connection Switch Condition Specified Condition H25-7 (AM2) - H25-6 (IG2) LOCK 10 kΩ or higher H25-7 (AM2) - H25-6 (IG2) ON Below 1 Ω

   
   
   • OKClick here
   • NGClick here
6. Click here

   CHECK ECM TERMINAL VOLTAGE (MREL TERMINAL)

   
   
   1. 

      Turn the ignition switch ON.

   2. Measure the voltage of the ECM connectors.

      Standard voltage
      Tester Connection Specified Condition B9-8 (MREL) - D3-7 (E1) 9 to 14 V

   
   
   • OKClick here
   • NGClick here
7. Click here

   INSPECT FUSE (EFI FUSE)

   
   
   1. 

      Remove the EFI fuse from the engine room J/B and K/B No.1.

   2. Measure the resistance of the fuse.

      Standard resistance
      Below 1 Ω

   
   
   • OKClick here
   • NGClick here
8. Click here

   INSPECT INTEGRATION NO.1 RELAY (MAIN RELAY)

   
   
   1. 

      Remove the integration relay from the engine room J/B and R/B No.1.

   2. Disconnect the 1J integration relay connector.

   3. Measure the voltage of the MAIN relay.

      Standard voltage
      Tester Connection Condition Specified Condition 1J-4 - Body ground Ignition switch ON 10 to 14 V

   
   
   • OKClick here
   • NGClick here
9. Click here

   CHECK HARNESS AND CONNECTOR (MAIN RELAY - ECM)

   
   
   1. 

      Disconnect the 1J integration relay connector from the engine room J/B and R/B No.1.

   2. Disconnect the B9 ECM connector.

   3. Measure the resistance of the wire harness side connectors.

      Standard resistance
      Tester Connection Specified Condition 1J-4 - B9-1 (+B) Below 1 Ω 1J-4 or B9-1 (+B) - Body ground 10 kΩ or higher

   
   
   • OKClick here
   • NGClick here
10. Click here

    REPAIR OR REPLACE HARNESS AND CONNECTOR (+B TERMINAL OF ECM - BATTERY POSITIVE TERMINAL)

11. Click here

    PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON PROBLEM SYMPTOMS TABLE

12. Click here

    REPAIR OR REPLACE HARNESS AND CONNECTOR

13. Click here

    CHECK FOR SHORT IN ALL HARNESS AND COMPONENTS CONNECTED TO FUSE, AND REPLACE FUSE

14. Click here

    REPLACE IGNITION SWITCH ASSEMBLY

15. Click here

    REPLACE ECM

16. Click here

    REPLACE INTEGRATION NO.1 RELAY

17. Click here

    REPAIR OR REPLACE HARNESS AND CONNECTOR (MAIN RELAY - ECM)