СИСТЕМА ECD ECM Power Source Circuit

DESCRIPTION

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

INSPECTION PROCEDURE

PROCEDURE

1. Click here

   CHECK ECM (+B VOLTAGE)

   
   

   1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition G61-12 (+B) - C101-14 (E1) Ignition switch ON 11 to 14 V

      Table 1. Text in Illustration

      *a	Component with harness connected (ECM)

   
   
   • OKClick here
   • NGClick here
2. 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 (Check for Open)
      Tester Connection Condition Specified Condition C101-14 (E1) - Body ground Always Below 1 Ω

      Table 2. Text in Illustration

      *a	Rear view of wire harness connector (to ECM)

   3. Reconnect the ECM connector.

   
   
   • OKClick here
   • NGClick here
3. Click here

   CHECK ECM (IGSW VOLTAGE)

   
   

   1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition G61-14 (IGSW) - C101-14 (E1) Ignition switch ON 11 to 14 V

      Table 3. Text in Illustration

      *a	Component with harness connected (ECM)

   
   
   • OKClick here
   • NGClick here
4. Click here

   CHECK ECM (MREL VOLTAGE)

   
   

   1. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition G61-3 (MREL) - C101-14 (E1) Ignition switch ON 11 to 14 V

      Table 4. Text in Illustration

      *a	Component with harness connected (ECM)

   
   
   • OKClick here
   • NGClick here
5. Click here

   CHECK NO. 1 INTEGRATION RELAY (EFI)

   
   

   1. Turn the ignition switch to ON.

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

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

      Table 5. Text in Illustration

      *a	Rear view of wire harness connector (to No. 1 Integration Relay)

   3. Reconnect the No. 1 integration relay (EFI) connector.

   
   
   • OKClick here
   • NGClick here
6. Click here

   CHECK HARNESS AND CONNECTOR (NO. 1 INTEGRATION RELAY (EFI) - ECM AND BODY GROUND)

   
   

   1. Disconnect the No. 1 integration relay (EFI) connector from the engine room junction 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 1B-2 - G61-3 (MREL) Always Below 1 Ω 1B-4 - G61-12 (+B) Always Below 1 Ω 1B-3 - Body ground Always Below 1 Ω

      Standard Resistance (Check for Short)
      Tester Connection Condition Specified Condition 1B-2 or G61-3 (MREL) - Body ground Always 10 kΩ or higher 1B-4 or G61-12 (+B) - Body ground Always 10 kΩ or higher

   4. Reconnect the No. 1 integration relay (EFI) connector.

   5. Reconnect the ECM connector.

   
   
   • OKClick here
   • NGClick here
7. Click here

   INSPECT IGNITION SWITCH ASSEMBLY

   
   

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

   
   
   • OKClick here
   • NGClick here
8. Click here

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

9. Click here

   REPAIR OR REPLACE HARNESS OR CONNECTOR

10. Click here

    REPLACE IGNITION SWITCH ASSEMBLYClick here

11. Click here

    REPLACE ECMClick here

12. Click here

    REPLACE NO. 1 INTEGRATION RELAY (EFI)

13. Click here

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

14. Click here

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