WARNING: In order to prevent flooding of cylinder and possible engine damage, relieve fuel pressure before performing injector coil test procedure.

Install scan tool. Using scan tool, check engine coolant temperature. If scan tool displays 50-95°F (10-35°C), go to next step. If scan tool does not display 50-95°F (10-35°C), perform injector coil test. See INJECTOR COIL TEST - ECT IS NOT 50-95°F .

NOTE: Perform step 2 on each injector.

Turn ignition off. Relieve fuel pressure. Disconnect fuel injector harness connectors. Using appropriate fuel injector adapter, connect Fuel Injector Tester (J-39021) to fuel injector. Connect fuel injector tester power leads to appropriate battery terminals. Set amperage supply selector switch on fuel injector tester to Coil Test 0.5-amp position. Connect DVOM to fuel injector tester. Depress PUSH TO START TEST button on injector tester. Record lowest voltage reading within first second of test. If any injector has erratic voltage reading or reading not 5.7-6.6 volts (8.0-8.5 volts on 3.0L engine), go to next step. If no injector has erratic voltage reading or reading not 5.7-6.6 volts (8.0-8.5 volts on 3.0L engine), perform fuel injector balance test. See FUEL INJECTOR BALANCE TEST .
Replace faulty injector(s) and perform fuel injector balance test. See FUEL INJECTOR BALANCE TEST .

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Injector Coil Test - ECT Is 50-95°F