SFI SYSTEM > Fuel Injector Circuit

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DESCRIPTION

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

WIRING DIAGRAM


A099747E05


INSPECTION PROCEDURE

1.CHECK ECM (#10, #20, #30, #40 VOLTAGE)
A066060E26

  1. Turn the ignition switch ON.



  1. Measure the voltage of the ECM connectors.

    Standard voltage:
    Tester Connection
    		Specified Condition
    E11-6 (#10) - E12-7 (E01)
    		9 to 14 V
    E11-5 (#20) - E12-7 (E01)
    		9 to 14 V
    E11-2 (#30) - E12-7 (E01)
    		9 to 14 V
    E11-1 (#40) - E12-7 (E01)
    		9 to 14 V


    A078423E07


    HINT:
    Reference: Inspect using the oscilloscope.
    Check the waveform of the ECM connector.
    Tester Connection
    		Specified Condition
    E11-6 (#10) - E12-7 (E01)
    		Correct waveform is as shown
    E11-5 (#20) - E12-7 (E01)
    		Correct waveform is as shown
    E11-2 (#30) - E12-7 (E01)
    		Correct waveform is as shown
    E11-1 (#40) - E12-7 (E01)
    		Correct waveform is as shown
    Tool Setting
    		Condition
    20 V/DIV., 100 or 1 msec./DIV.
    		Idling



OK
Go to step 6
NG


2.INSPECT FUEL INJECTOR ASSEMBLY (RESISTANCE)
Click here


NG
REPLACE FUEL INJECTOR ASSEMBLY
OK


3.INSPECT FUSE (INJ)
G034710E03

  1. Remove the INJ fuse from the instrument panel junction block.

  1. Measure the resistance of the fuse.

    Standard resistance:
    Below 1 Ω



NG
CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE
OK


4.CHECK WIRE HARNESS OF MISFIRING CYLINDER (INJECTOR - ECM, INJECTOR - INJ FUSE)
G034950E02

  1. Check the wire harness between the injector and ECM.

    1. Disconnect the F5, F6, F7 and/or F8 injector connectors.

    2. Disconnect the E11 ECM connector.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance:
      Tester Connection
      		Specified Condition
      F5-2 - E11-6 (#10)
      		Below 1 Ω
      F6-2 - E11-5 (#20)
      		Below 1 Ω
      F7-2 - E11-2 (#30)
      		Below 1 Ω
      F8-2 - E11-1 (#40)
      		Below 1 Ω
      F5-2 or E11-6 (#10) - Body ground
      		10 kΩ or higher
      F6-2 or E11-5 (#20) - Body ground
      		10 kΩ or higher
      F7-2 or E11-2 (#30) - Body ground
      		10 kΩ or higher
      F8-2 or E11-1 (#40) - Body ground
      		10 kΩ or higher

  1. Check the wire harness between the injector and INJ fuse.

    1. Disconnect the F5, F6, F7 and F8 injector connectors.

    2. Remove the INJ fuse from the instrument panel junction block.

    3. Measure the resistance of the wire harness side connectors.

      Standard resistance:
      Tester Connection
      		Specified Condition
      F5-1 - J/B INJ fuse terminal 2
      		Below 1 Ω
      F6-1 - J/B INJ fuse terminal 2
      		Below 1 Ω
      F7-1 - J/B INJ fuse terminal 2
      		Below 1 Ω
      F8-1 - J/B INJ fuse terminal 2
      		Below 1 Ω
      F5-1 or J/B INJ fuse terminal 2 - Body ground
      		10 kΩ or higher
      F6-1 or J/B INJ fuse terminal 2 - Body ground
      		10 kΩ or higher
      F7-1 or J/B INJ fuse terminal 2 - Body ground
      		10 kΩ or higher
      F8-1 or J/B INJ fuse terminal 2 - Body ground
      		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


5.CHECK WIRE HARNESS (IGNITION SWITCH - INJ FUSE)
G034709E02

  1. Disconnect the I6 ignition switch connector.

  1. Remove the INJ fuse from the instrument panel junction block.

  1. Measure the resistance of the wire harness side connectors.

    Standard resistance:
    Tester Connection
    		Specified Condition
    I6-6 (IG2) - J/B INJ fuse terminal 1
    		Below 1 Ω
    I6-6 (IG2) or J/B INJ fuse terminal 1 - Body ground
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK

CHECK FOR ECM POWER SOURCE CIRCUIT 

6.CHECK WIRE HARNESS (ECM - BODY GROUND)
A065159E04

  1. Disconnect the E12 ECM connector.

  1. Measure the resistance of the wire harness side connector.

    Standard resistance:
    Tester Connection
    		Specified Condition
    E12-7 (E01) - Body ground
    		Below 1 Ω
    E12-6 (E02) - Body ground
    		Below 1 Ω



NG
REPAIR OR REPLACE HARNESS AND CONNECTOR
OK


7.INSPECT FUEL INJECTOR ASSEMBLY (CHECK FUEL INJECTION VOLUME)
Click here


NG
REPLACE FUEL INJECTOR ASSEMBLY
OK

PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE