Fuel Injector Circuit Check: Troubleshooting

NOTE:

Before performed troubleshooting, be sure to read the Precautions of ECM Circuit Inspection.
When measuring circuit voltage, resistance and/or pulse signal at ECM connector, connect the special tool to ECM and/or the ECM connectors referring to INSPECTION OF ECM AND ITS CIRCUITS .

DTC TROUBLESHOOTING CHART

Step	Action	YES	NO
1	Fuel injector check for operating sound Using sound scope, check each injector for operating sound at engine cranking. Do all 6 injector make operating sound?	Fuel injectors circuit is in good condition.	Go to Step 2.
2	Fuel injector resistance check Disconnect connectors from fuel injectors with ignition switch turned OFF. Check for proper terminal connection to all fuel injectors and ECM connector. If connections are OK, check all fuel injectors for resistance referring to FUEL INJECTOR ON-VEHICLE INSPECTION . Are all injectors in good condition?	Go to Step 3.	Faulty fuel injector.
3	Fuel injector insulation resistance check Check that there is insulation between each fuel injector terminal and engine ground. Is there insulation?	Go to Step 4.	Faulty fuel injector.
4	Fuel injector power supply check Measure voltage between each fuel injector connector power supply circuit and engine ground with ignition switch turned ON. Is each voltage 10 - 14 V?	Go to Step 5.	Fuel injector power supply circuit is open or shorted to ground circuit. If it is in good condition, go to ECM POWER AND GROUND CIRCUIT CHECK .
5	Wire harness check Disconnect connector from ECM with ignition switch turned OFF. Check that each fuel injector circuit is as follows. Wiring harness resistance of each fuel injector control circuit is less than 3 Ω Insulation resistance of each fuel injector control circuit is infinity between each fuel injector connector and vehicle body ground Circuit voltage of each fuel injector control circuit is 0 - 1 V with ignition switch turned ON Are they in good condition?	Check fuel injector for performance referring to FUEL INJECTOR INSPECTION . If OK, substitute a known-good ECM and recheck.	Fuel injector control circuit is open, short or high resistance.