Case IH 19917 – Engine Control Unit (ECU): Error in comparing energizing time to minimum value for injector in cylinder 3

The actual electrical energizing time required to fire the cylinder 3 injector falls below the minimum acceptable threshold programmed into the module during Zero Fuel Calibration (ZFL). This typically points to an internal mechanical wear issue within the injector (causing it to react too quickly/erratically) or a resistance issue in the injector circuit.

• Tier 4b
• Case IH Tractors (Farmall, Maxxum, Puma series)
• Case Construction Equipment (N-Series Loader Backhoes)

1. 1

   Connect the CNH Electronic Service Tool (EST), clear the fault code, and let the engine run at low idle to allow the ECU to perform a new Zero Fuel Calibration (ZFL) to verify if the code returns

2. 2

   Check the wiring harness from the ECU to the cylinder 3 injector for chafing, shorts to ground, or loose connector pins that could alter circuit resistance

3. 3

   Ensure there is no air intrusion in the fuel system and that fuel filters are clean, as poor fuel supply can cause the ECU to overcompensate

4. 4

   Use the EST to perform a cylinder cutout test or injector balance test to confirm if cylinder 3 is underperforming mechanically

1. 1

   Preparation

   Disconnect the battery. Thoroughly clean the area around the cylinder 3 fuel injector to prevent debris from entering the engine.

2. 2

   Depressurize

   Relieve the fuel system pressure according to the OEM service manual.

3. 3

   Removal

   Disconnect the electrical connector from the cylinder 3 injector. Remove the high-pressure fuel line connecting the common rail to the cylinder 3 injector. Remove the injector hold-down clamp/bolt. Carefully extract the injector from the cylinder head.

4. 4

   Installation

   Clean the injector bore in the cylinder head. Install the new injector using a new copper sealing washer and O-ring. Reinstall the hold-down clamp and torque the bolt to the specific engine's OEM torque spec. Install a new high-pressure fuel line and torque the fittings. Reconnect the electrical harness.

5. 5

   ECU Programming

   You must use the CNH Electronic Service Tool (EST) to enter the new injector's trim code (IQA code, printed on the top of the new injector) into the ECU. If this is not done, the ZFL calibration will be incorrect.

6. 6

   Verification

   Prime the fuel system, start the engine, and let it idle so the ECU can relearn the ZFL parameters. Verify that code 19917 does not return.