Fuel Injector Solenoid Coil Test

Diagnostic Instructions

Circuit/System Description

The engine control module (ECM) supplies a separate high control and low control circuit for each fuel injector. The ECM energizes each fuel injector by grounding the low control circuit. The ECM controls each fuel injector with 65 V. This is controlled by a boost capacitor in the ECM. During the 65 V boost phase, the capacitor is discharged through a fuel injector, allowing for initial fuel injector opening. The fuel injector is then held open with 12 V. A fuel injector coil winding resistance that is too high or too low will affect the engine driveability. The fuel injector coil windings are affected by temperature. The resistance of the fuel injector coil windings will increase as the temperature of the fuel injector increases.

Reference Information

Schematic Reference

Engine Controls Schematics

Electrical Information Reference

Component Testing

Note:

  • The resistance test must be performed at the fuel injector or mis-diagnosis will occur.
  • The DMM and test leads must be calibrated to 0 Ω in order to prevent mis-diagnosis.

  1. Ignition OFF, all vehicle system OFF, disconnect the harness connector at the appropriate Q17 Fuel Injector.
  2. Test for 1.9–2.3 Ω at 20°C (68°F) between terminal A and terminal B at the Q17 Fuel Injector.
    • If not within the specified range

      Replace the Q17 Fuel Injector.

    • If within the specified range
  3. Verify infinite resistance between each terminal at the Q17 Fuel Injector and the fuel injector housing/case.
    • If less than infinite resistance

      Replace the Q17 Fuel Injector

    • If infinite resistance
  4. All OK, perform the Fuel Injector Balance Test.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

Fuel Injector Replacement