Fuel Injector Circuit Check: Troubleshooting

NOTE: The connectors of the ECM are watertight. If tester probes are directly connected to any of the connectors when checking the ECM and its circuits, the watertight performance of the connector will be affected, possibly resulting in corrosion of connector terminals and damage to electrical circuits. Always use the special tool when checking the circuits. Connect tester probes only to the special tool's connectors.

DIAGNOSTIC PROCEDURE CHART

Step	Action	YES	NO
1	Fuel injector check for operating sound Using sound scope, check each injector for operating sound with engine cranking. Do all injectors make operating sound?	Fuel injector circuit is in good condition.	Go to Step 2.
2	Fuel injector resistance check Confirm that ignition mode of keyless push start system is "OFF". Disconnect connectors from fuel injectors. Check for proper connection to fuel injector at each terminals. If OK, check all fuel injectors for resistance, see FUEL INJECTOR ON-VEHICLE INSPECTION . Are all injectors at specified resistance?	Go to Step 3.	Replace fuel injector, see FUEL INJECTOR REMOVAL AND INSTALLATION .
3	Fuel injector insulation resistance check Check that resistance between each fuel injector terminal and engine ground is infinity. Are they in good condition?	Go to Step 4.	Replace fuel injector, see FUEL INJECTOR REMOVAL AND INSTALLATION .
4	Fuel injector power supply circuit check Push engine switch to change ignition mode to "ON". Check that voltage between each fuel injector power supply circuit (B1, B2, B3, B4) and engine ground is battery voltage, see FUEL INJECTOR CONTROL SYSTEM CIRCUIT DIAGRAM . Is it in good condition?	Go to Step 5.	Repair fuel injector power supply circuit. If it is in good condition, go to ECM POWER AND GROUND CIRCUIT CHECK .
5	Fuel injector drive circuit check Confirm that ignition mode of keyless push start system is "OFF". Disconnect connectors from ECM. Check the following points, see FUEL INJECTOR CONTROL SYSTEM CIRCUIT DIAGRAM . Resistance of each fuel injector drive circuit (A1, A2, A3, A4): less than 3 Ω Resistance between each fuel injector drive circuit and ground: infinity Voltage of each fuel injector drive circuit: 0 - 1 V (with the ignition mode of keyless push start system in "ON") Are they in good condition?	Go to Step 6.	Repair fuel injector drive circuit.
6	Fuel injector check Check fuel injector, see FUEL INJECTOR REMOVAL AND INSTALLATION . Is it in good condition?	Replace ECM and recheck DTC, see ECM REMOVAL AND INSTALLATION .	Replace fuel injector, see FUEL INJECTOR REMOVAL AND INSTALLATION .