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 .

TROUBLESHOOTING PROCEDURES

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 4 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 connection to fuel injector at each terminals. If OK, check all 4 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 "BLK/RED" wire terminal of fuel injector connector and engine ground with ignition switch turned ON. Is voltage 10 - 14 V?	Go to Step 5.	"BLK/RED" wire is open or shorted to ground circuit. If it is in good condition, go to ECM POWER AND GROUND CIRCUIT CHECK .
5	Wire circuit check Turn OFF ignition switch. Disconnect connectors from ECM. Measure resistance between each "BLU/YEL", "BLU/WHT", "BLU/RED", "BLU/ORN" wire terminal of fuel injector connector and vehicle body ground. Is resistance infinity?	Go to Step 6.	"BLU/YEL", "BLU/WHT", "BLU/RED" and/or "BLU/ORN" wire(s) are shorted to ground.
6	Wire circuit check Measure voltage between each "BLU/YEL", "BLU/WHT", "BLU/RED", "BLU/ORN" wire terminal of fuel injector connector and vehicle body ground with ignition switch turned ON. Is voltage 0 V?	Go to Step 7.	"BLU/YEL", "BLU/WHT", "BLU/RED" and/or "BLU/ORN" wire(s) are shorted to power supply circuit.
7	Fuel injector drive signal check Connect connectors to each fuel injector and ECM with ignition switch turned OFF. Turn ON ignition switch. Measure voltage between each "C01-1", "C01-2", "C01-16", "C01-17" terminal of ECM connector and vehicle body ground. Is voltage 10 - 14 V?	Check fuel injector referring to FUEL INJECTOR INSPECTION . If check result is satisfactory, substitute a known-good ECM and recheck.	"BLU/YEL", "BLU/WHT", "BLU/RED" and/or "BLU/ORN" wire(s) are open circuit.