SFI SYSTEM (w/o Secondary Air Injection System) Injector Circuit

DESCRIPTION

The fuel injectors are located on the intake manifold. They inject fuel into the cylinders based on the signals from the ECM.

Reference: INSPECTION USING OSCILLOSCOPE

With the engine idling, check the waveform between terminals #1 to #4 and E01 of the ECM connectors.

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. INSPECT ECM (#1, #2, #3 or #4 VOLTAGE)

   
   

   1. 

      Turn the ignition switch to the ON position.

   2. Measure the voltage between the terminals of the ECM connector.

      Voltage
      Tester Connections Specified Conditions #1 (D3-6) - E01 (D1-7) 9 to 14 V #2 (D3-5) - E01 (D1-7) 9 to 14 V #3 (D3-2) - E01 (D1-7) 9 to 14 V #4 (D3-1) - E01 (D1-7) 9 to 14 V

   
   

   OK

   CHECK HARNESS OR CONNECTOR (ECM GROUND) Click here

   NG

2. INSPECT FUEL INJECTOR ASSEMBLY

   
   

   NG

   REPLACE FUEL INJECTOR ASSEMBLY

   OK

3. CHECK HARNESS OR CONNECTOR (INJECTOR - ECM, INJECTOR - IGNITION SWITCH)

   
   

   1. 

      Check the harness and connectors between the injector and ECM.

      
      

      1. Disconnect the injector connector(s).

      2. Disconnect the D3 ECM connector.

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

         Resistance (Check for open)
         Tester Connection Specified Condition Injector (D24-2) - #1 (D3-6) Below 1 Ω Injector (D25-2) - #2 (D3-5) Below 1 Ω Injector (D26-2) - #3 (D3-2) Below 1 Ω Injector (D27-2) - #4 (D3-1) Below 1 Ω

         Resistance (Check for short)
         Tester Connection Specified Condition Injector (D24-2) or #1 (D3-6) - Body ground 10 kΩ or higher Injector (D25-2) or #2 (D3-5) - Body ground 10 kΩ or higher Injector (D26-2) or #3 (D3-2) - Body ground 10 kΩ or higher Injector (D27-2) or #4 (D3-1) - Body ground 10 kΩ or higher

      4. Reconnect the injector connector(s).

      5. Reconnect the ECM connector.

   2. Check the harness and connectors between the injector and ignition switch.

      
      

      1. Disconnect the injector connector(s).

      2. Disconnect the H25 ignition switch connector.

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

         Resistance (Check for open)
         Tester Connection Specified Condition Injector (D24-1) - IG2 (H25-6) Below 1 Ω Injector (D25-1) - IG2 (H25-6) Below 1 Ω Injector (D26-1) - IG2 (H25-6) Below 1 Ω Injector (D27-1) - IG2 (H25-6) Below 1 Ω

         Resistance (Check for short)
         Tester Connection Specified Condition Injector (D24-1) or IG2 (H25-6) - Body ground 10 kΩ or higher Injector (D25-1) or IG2 (H25-6) - Body ground 10 kΩ or higher Injector (D26-1) or IG2 (H25-6) - Body ground 10 kΩ or higher Injector (D27-1) or IG2 (H25-6) - Body ground 10 kΩ or higher

      4. Reconnect the injector connector.

      5. Reconnect the ignition switch connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

   CHECK ECM POWER SOURCE CIRCUIT

4. CHECK HARNESS OR CONNECTOR (ECM GROUND)

   
   

   1. 

      Disconnect the D1 ECM Connector.

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

      Resistance
      Tester Connection Specified Condition E01 (D1-7) - Body ground Below 1 Ω E02 (D1-6) - Body ground Below 1 Ω

   3. Reconnect the ECM connector.

   
   

   NG

   REPAIR OR REPLACE HARNESS OR CONNECTOR

   OK

5. INSPECT FUEL INJECTOR ASSEMBLY

   
   

   NG

   REPLACE FUEL INJECTOR ASSEMBLY

   OK

   PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE