SFI SYSTEM Fuel Injector Circuit

DESCRIPTION

The fuel injector assemblies are located on the intake port. They inject fuel into the cylinders based on the signals from the ECM.

CAUTION / NOTICE / HINT

PROCEDURE

1. Click here

   CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR ASSEMBLY)

   
   
   1. 

      *a	Front view of wire harness connector (to Fuel Injector Assembly)

      Disconnect the fuel injector assembly connectors.

   2. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition C18-1 - Body ground Ignition switch ON 11 to 14 V C19-1 - Body ground Ignition switch ON 11 to 14 V C20-1 - Body ground Ignition switch ON 11 to 14 V C21-1 - Body ground Ignition switch ON 11 to 14 V

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NGClick here
2. Click here

   INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)

   
   

   1. Check the fuel injector assembly injection and volume.

      Click here

      Tip:

      Perform "Inspection After Repair" after replacing the fuel injector assembly.

      Click here

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NG

     REPLACE FUEL INJECTOR ASSEMBLYClick here

3. Click here

   CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

   
   

   1. Disconnect the ECM connector.

   2. Disconnect the fuel injector assembly connector.

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

      Standard Resistance

      Tester Connection Condition Specified Condition C18-2 - C53-4 (#10) Always Below 1 Ω C19-2 - C53-3 (#20) Always Below 1 Ω C20-2 - C53-2 (#30) Always Below 1 Ω C21-2 - C53-1 (#40) Always Below 1 Ω C18-2 or C53-4 (#10) - Body ground Always 10 kΩ or higher C19-2 or C53-3 (#20) - Body ground Always 10 kΩ or higher C20-2 or C53-2 (#30) - Body ground Always 10 kΩ or higher C21-2 or C53-1 (#40) - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   
   • OK

     PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLEClick here

   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

4. Click here

   CHECK HARNESS AND CONNECTOR (INJ RELAY - FUEL INJECTOR ASSEMBLY)

   
   

   1. Disconnect the fuel injector assembly connector.

   2. Remove the INJ relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition C18-1 - INJ relay terminal 3 Always Below 1 Ω C19-1 - INJ relay terminal 3 Always Below 1 Ω C20-1 - INJ relay terminal 3 Always Below 1 Ω C21-1 - INJ relay terminal 3 Always Below 1 Ω C18-1, C19-1, C20-1, C21-1 or INJ relay terminal 3 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

5. Click here

   INSPECT INJ RELAY

   
   

   1. Inspect the INJ relay.

      Click here

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NG

     REPLACE INJ RELAY

6. *1 Engine Room Relay Block Assembly *2 INJ Relay
   Click here

   CHECK TERMINAL VOLTAGE (POWER SOURCE OF INJ RELAY)

   
   

   1. Remove the INJ relay from the engine room relay block and junction block assembly.

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

      Standard Voltage
      Tester Connection Condition Specified Condition INJ relay terminal 5 - Body ground Always 11 to 14 V

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

7. Click here

   CHECK HARNESS AND CONNECTOR (INJ RELAY - BODY GROUND)

   
   

   1. Remove the INJ relay from the engine room relay block and junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition INJ relay terminal 1 - Body ground Always Below 1 Ω

      Result
      Proceed to OK NG

   
   
   • OKClick here
   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR

8. Click here

   CHECK HARNESS AND CONNECTOR (INJ RELAY - INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY)

   
   

   1. Remove the INJ relay from the engine room relay block and junction block assembly.

   2. Disconnect the instrument panel junction block assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition INJ relay terminal 2 - 2K-4 Always Below 1 Ω INJ relay terminal 2 or 2K-4 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   
   • OK

     GO TO ECM POWER SOURCE CIRCUITClick here

   • NG

     REPAIR OR REPLACE HARNESS OR CONNECTOR