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

NOTE: Perform step 2 on each injector.

Turn ignition off. Relieve fuel pressure. Disconnect fuel injector harness connectors. Using 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 injector tester. Depress PUSH TO START TEST button on injector tester. Record highest voltage reading other than those greater than 9.5 volts. Subtract any other voltage reading observed from highest voltage reading. If difference is greater than 0.6 volt (0.7 volt on 2.2L and 2.4L), go to next step. If difference is not greater than 0.6 volt (0.7 volt on 2.2L and 2.4L), perform fuel injector balance test. See FUEL INJECTOR BALANCE TEST .
Replace any injector(s) that had any of the following results: initial reading greater than 9.5 volts, erratic reading or difference is greater than 0.6 volt (0.7 volt on 2.2L and 2.4L). After repairs, 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 Not 50-95°F