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.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

PROCEDURE

1. CHECK TERMINAL VOLTAGE (POWER SOURCE OF FUEL INJECTOR ASSEMBLY)

   

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

   
   

   1. 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 Condition Specified Condition C123-2 - Body ground Ignition switch ON 11 to 14 V C19-2 - Body ground Ignition switch ON 11 to 14 V C124-2 - Body ground Ignition switch ON 11 to 14 V C21-2 - Body ground Ignition switch ON 11 to 14 V C22-2 - Body ground Ignition switch ON 11 to 14 V C23-2 - Body ground Ignition switch ON 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

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

   OK

2. INSPECT FUEL INJECTOR ASSEMBLY

   
   

   1. Inspect the fuel injector assembly.

      Click here

      Tech Tips

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

      Click here

      Result
      Proceed to OK NG

   
   

   NG

   REPLACE FUEL INJECTOR ASSEMBLY Click here

   OK

3. CHECK HARNESS AND CONNECTOR (FUEL INJECTOR ASSEMBLY - ECM)

   
   

   1. Disconnect the fuel injector assembly connectors.

   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 C123-1 - C12-6 (#10) Always Below 1 Ω C19-1 - C12-1 (#20) Always Below 1 Ω C124-1 - C12-7 (#30) Always Below 1 Ω C21-1 - C12-2 (#40) Always Below 1 Ω C22-1 - C12-8 (#50) Always Below 1 Ω C23-1 - C12-3 (#60) Always Below 1 Ω C123-1 or C12-6 (#10) - Body ground and other terminals Always 10 kΩ or higher C19-1 or C12-1 (#20) - Body ground and other terminals Always 10 kΩ or higher C124-1 or C12-7 (#30) - Body ground and other terminals Always 10 kΩ or higher C21-1 or C12-2 (#40) - Body ground and other terminals Always 10 kΩ or higher C22-1 or C12-8 (#50) - Body ground and other terminals Always 10 kΩ or higher C23-1 or C12-3 (#60) - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

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

   
   

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

   2. Disconnect the fuel injector assembly connectors.

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

      Standard Resistance

      Tester Connection Condition Specified Condition INJ relay terminal 3 - C123-2 Always Below 1 Ω INJ relay terminal 3 - C19-2 Always Below 1 Ω INJ relay terminal 3 - C124-2 Always Below 1 Ω INJ relay terminal 3 - C21-2 Always Below 1 Ω INJ relay terminal 3 - C22-2 Always Below 1 Ω INJ relay terminal 3 - C23-2 Always Below 1 Ω INJ relay terminal 3 or C123-2 - Body ground and other terminals Always 10 kΩ or higher INJ relay terminal 3 or C19-2 - Body ground and other terminals Always 10 kΩ or higher INJ relay terminal 3 or C124-2 - Body ground and other terminals Always 10 kΩ or higher INJ relay terminal 3 or C21-2 - Body ground and other terminals Always 10 kΩ or higher INJ relay terminal 3 or C22-2 - Body ground and other terminals Always 10 kΩ or higher INJ relay terminal 3 or C23-2 - Body ground and other terminals Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   GO TO ECM POWER SOURCE CIRCUIT Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR