SFI SYSTEM Fuel Injector Circuit

DESCRIPTION

The fuel injectors are located on the intake manifold. They inject fuel into the cylinders based on 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 C25-1 - Body ground Ignition switch ON 11 to 14 V C26-1 - Body ground Ignition switch ON 11 to 14 V C28-1 - Body ground Ignition switch ON 11 to 14 V C29-1 - Body ground Ignition switch ON 11 to 14 V

      Result
      Proceed to OK NG

   
   

   NG

   CHECK HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - FUEL INJECTOR ASSEMBLY) Click here

   OK

2. INSPECT FUEL INJECTOR ASSEMBLY (INJECTION AND VOLUME)

   
   

   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 connector.

   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 C25-2 - C1-20 (#10) Always Below 1 Ω C26-2 - C1-17 (#20) Always Below 1 Ω C28-2 - C1-18 (#30) Always Below 1 Ω C29-2 - C1-19 (#40) Always Below 1 Ω C25-2 or C1-20 (#10) - Body ground Always 10 kΩ or higher C26-2 or C1-17 (#20) - Body ground Always 10 kΩ or higher C28-2 or C1-18 (#30) - Body ground Always 10 kΩ or higher C29-2 or C1-19 (#40) - Body ground 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 (SEMICONDUCTOR PWR INTEGRATION ECU - FUEL INJECTOR ASSEMBLY)

   
   

   1. Disconnect the fuel injector assembly connector.

   2. Disconnect the semiconductor pwr integration ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition C25-1 - 1G-3 Always Below 1 Ω C26-1 - 1G-3 Always Below 1 Ω C28-1 - 1G-3 Always Below 1 Ω C29-1 - 1G-3 Always Below 1 Ω C25-1, C26-1, C28-1, C29-1 or 1G-3 - Body ground Always 10 kΩ or higher

      Result
      Proceed to OK NG

   
   

   OK

   CHECK ECM POWER SOURCE CIRCUIT Click here

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR