1A
Fuel Injector Circuit Check
Wiring Diagram
1. Relay box 4. No.1 injector 7. No.4 injector 10. “FI” fuse
2. Main relay 5. No.2 injector 8. “IG” fuse 11. “IGN1” fuse
3. ECM 6. No.3 injector 9. Ignition switch      
Troubleshooting
Step Action YES NO
1
Fuel injector check for operating sound
1) Using sound scope, check each injector for operating sound at engine cranking.
Do all 4 injector make operating sound?
Fuel injector circuit is in good condition.
Go to Step 2.
2
Fuel injector resistance check
1) Disconnect connectors from fuel injectors with ignition switch turn OFF.
2) Check for proper connection to fuel injector at each terminals.
3) If OK, check all 4 fuel injectors for resistance referring to Fuel Injector On-Vehicle Inspection:M13A .
Are all injectors in good condition?
Go to Step 3.
Faulty fuel injector.
3
Fuel injector insulation resistance check
1) Check that there is insulating between each fuel injector terminals and engine ground.
Is there insulating?
Go to Step 4.
Faulty fuel injector.
4
Fuel injector power supply check
1) Measure voltage between each “BLU/BLK” wire terminal of fuel injector connector and engine ground with ignition switch turned ON.
Is voltage 10 – 14 V?
Go to Step 5.
“BLU/BLK” wire in open circuit or shorted to ground circuit.
If it is in good condition, go to MIL Does Not Light with Ignition Switch ON and Engine Does Not Start Though It Is Cranked Up:M13A with VVT .
5
Wire circuit check
1) Turn OFF ignition switch.
2) Disconnect connectors from ECM.
3) Measure resistance between each “RED/ WHT”, “RED/GRN”, “WHT/GRN”, “WHT/ BLK” wire terminal of fuel injector connector and vehicle body ground.
Is resistance infinity?
Go to Step 6.
“RED/WHT”, “RED/GRN”, “WHT/GRN”, “WHT/BLK” wire shorted to ground.
6
Wire circuit check
1) Measure voltage between each “RED/ WHT”, “RED/GRN”, “WHT/GRN”, “WHT/ BLK” wire terminal of fuel injector connector and vehicle body ground with ignition switch turned ON.
Is voltage 0 V?
Go to Step 7.
“RED/WHT”, “RED/GRN”, “WHT/GRN”, “WHT/BLK” wire shorted to power supply circuit.
7
Fuel injector drive signal check
1) Connect connectors to each fuel injectors and ECM with ignition switch turned OFF.
2) Turn ON ignition switch.
3) Measure voltage between each “E119-7”, “E119-6”, “E119-5”, “E119-4” terminal of ECM connector and vehicle body ground.
Is voltage 10 – 14 V?
Check fuel injector referring to Fuel Injector Inspection:M13A .
If result in good condition, substitute a known-good ECM and recheck.
“RED/WHT”, “RED/GRN”, “WHT/GRN”, “WHT/BLK” open circuit.